List of All New Features in WordPress 3.4 Version

   Enhanced theme control

•         Customize theme options before activating a new theme using Theme Customizer
•         Use Theme Previewer to customize current theme without changing the front-end design

    Custom Headers

•         Improved Custom Headers with flexible sizes
•         Selecting Custom Header Images and Custom Background Images from Media Library Screen

    Media improvements

•         Support HTML in image captions

    Under the Hood improvements

•         Improvements in WordPress internationalization and localization
•         Different split in translation POT files for faster translations
•         Codex XML-RPC information update accessed via XML-RPC_WordPress_API
•         WP_Query improvements

User Features

General

•     Properly reflect the language on RSS feeds
•     Add support for DFW for all instances of the editor
•     Update license.txt to include ‘How to Apply These Terms to Your New Programs’ at the request of the FSF http://www.gnu.org/licenses/gpl-2.0.txt

Dashboard

•     Dashboard Widgets are available for translation
•     Help Tabs improvements
•     Remove Recently Updated from Plugins widget
•     Add a link to the Customizer from the Admin Bar appearance menu
•     Improve the Recent Comments dashboard widget performance on sites with large amounts of comments

Posts

•     Add new comment from post edit screen
•     Display menu_order value in Quick Edit for non-hierarchical post types
•     Change ‘Post Format’ bulk/quick edit label to ‘Format’

Media

•     HTML support has been added to image caption field
•     Add Twitter.com as an oEmbed providers

Links

•     Default Links are now available for translation

Comments

•     Remove “Approve” bulk action when viewing spam comments as it isn’t shown in the row actions

Appearance

•     Update the Theme Customizer in Twenty Ten and Twenty Eleven themes
•     Faster theme searching
•     Post formats should show_in_nav_menus when the current theme supports them
•     Infinite scroll for themes.php and theme-install.php. Bump per page limit for themes.php to 999
•     Add Sort by, and Number of Links to show, to the Links widget
•     Introduce new registration methods for custom headers and custom backgrounds
•     Default to keyword searches for the theme installer
•     Contextual help updates
•     Update install screens to use the new stars

Plugins

•     Clean up the Plugin installer screenshots page; adds CSS resize support to the images to prevent them requiring scrolling and falling below the FYI box
•     Default to keyword searches for the plugin installer
•     Update install screens to use the new stars

Tools

•     Bump WXR_VERSION because of plugins trac 501867 / r19858 which affects the regex based importer
•    Update contextual help

Users

•     After adding a user, take them back to users.php with an ‘Edit user’ link in the message
•     Correct how “Display name publicly as” works when other name fields change

Settings

•     Update color scheme definition for gray admin theme
•     Use blue arrows for blue admin’s screen options and help tabs; adjust baseline to be more compatible with Firefox
•     Timezone and start of week can now be specify through translated strings (rather than PHP)

Install Process

•     Don’t allow empty database prefix for multisite
•     Issue an error during the WordPress install process if wp-config.php is configured with an empty database table prefix, which is not supported
•     Remove references to specific search engines

Multisite

•     Better checking for values for multisite upload limit
•     Only allow _multisite_ super admins to demote themselves on a site
•     Create a network/about.php page and leverage it, to prevent the dashboard from switching to the blog admin
•     Add an “Edit Site” submenu to the admin bar site menu when a super admin visits a blog dashboard
•     Autocomplete for add-user screens
•     Do not save the last visited tab on the multisite Network Themes page and Site Themes tab
•     Make ‘Network Activate’ a bulk action on network/plugins.php
•     Increase default upload space for sites on a network from 10M to 100M
•     Clean up plugins.php with regards to recently edited files, deactivations, and the network admin

Development, Themes, Plugins

•     Add a filter to wp_terms_checklist() that wraps the function’s arguments; mainly designed to allow checked_ontop to be turned off
•     Add WP_Screen methods get_help_tabs(), get_help_tab( $id ), get_help_sidebar(). Store help tabs by tab ID, not numeric key; allows proper removal with remove_help_tab( $id )
•     Add ‘ep_mask’ as an argument to the ‘rewrite’ array for register_post_type() and register_taxonomy(); keeps ‘permalink_epmask’ compatible as an argument for post type registrations; fixes endpoints for category and tag pages
•     Add jQuery UI Touch Punch plugin to handle dragging on mobile devices
•     Add post ID argument to _wp_post_thumbnail_html() rather than relying on a global; post the ID from wp_ajax_set_post_thumbnail()
•     Add ‘search_columns’ arg to WP_User_Query to allow for explicit column choices; without it columns will be detected based on the search term
•     Add the editor ID and the post type (when available) as classes to the TinyMCE’s body
•     Add $id parameter to get_the_tag_list() for consistency with get_the_(category|term)_list().
•     Allow get_post_meta() to be called with only a post ID, as get_metadata() handles this
•     Allow counting by characters in lieu of a word count, for East Asian languages
•     Allow toolbar submenus to expand to the width of the parent item
•     Allow translators to specify a default timezone string OR GMT offset. Stop doing date(‘Z’)/3600 math for default ‘gmt_offset’
•     AtomServer class moved to wp-includes/class-wp-atom-server.php
•     Change the image caption shortcode format to  caption text + html
•     ; that way HTML tags in captions are better supported and the shortcode wouldn’t break when using the wrong quotes
•     Check the return of wp_insert_term() for WP_Error or array; prevents fatal errors and failure to add categories when adding terms via ajax
•     Cleanup and better document create_initial_taxonomies()
•     Clear strict notices for the walkers
•     Compress CSS/JS using the latest version of YUI Compressor
•     Create WP_Customize_Control to separate the process of rendering a control from fetching, previewing, and saving its value
•     Database schema change: Change ‘post_content_filtered’ to longtext in ‘wp_posts’ table
•     Database schema change: Drop ‘comment_approved’ index from ‘wp_comments’ table
•     Database schema change: Remove ‘blog_id’ column from ‘wp_options’ table
•     Define WPINC in wp-load when not set in wp-config.php
•     Deprecate add_custom_background() in favor of add_theme_support( ‘custom-background’ )
•     Deprecate add_custom_image_header() in favor of add_theme_support( ‘custom-header’ )
•     Deprecate display_theme()
•     Deprecate get_theme_data() in favor of wp_get_theme()
•     Do not block file mod/edit caps when DISALLOW_UNFILTERED_HTML is set; There are separate constants (DISALLOW_FILE_EDIT and DISALLOW_FILE_MODS for those)
•     Fix the return value of get_theme_root() when the theme root is outside of WP_CONTENT_DIR, thus making it absolute rather than the typical relative theme root; make get_theme_root_uri() tolerate an absolute path for a theme root; it will now make an attempt to find a corresponding URL for absolute paths as well.
•     Fixed “https” detection in feed generator
•     Formatting and i18n cleanup of repair.php
•     Hash post password in cookies
•     Improve adding more css classes to the editor body, add “rtl”, “ie7″, “ie8″, “ie9″ so they can be targeted in editor-style.css
•     Improve efficiency of make_clickable()
•     Improve wp-app.php; put the atom server class in class-wp-atom-server.php; remove log_api calls; update the query filter; replace exit calls with wp_die() for unit test compat; add override handler for wp_die(); allow plugins to replace the atom class
•     In case of 404, redirect /login, /dashboard, /admin to corresponding WordPress equivalents
•     Introduce $wpdb->delete()
•     Introduce set_header_image(), remove_header_image(), reset_header_image() and get_header_image_data()
•     Introduce WP_Theme class, wp_get_themes(), and wp_get_theme() to replace get_themes(), get_theme(), get_theme_data(), current_theme_info(), and others
•     Introduce __return_null()
•     Introduce display_header_text()
•     Introduce get_page_template_slug( $id = null ) to return a page’s template (like “showcase.php”); returns false if post ID is not a page, and an empty string for the default page template; use the function across core
•     Introduce sanitize_trackback_urls(); don’t ping bad urls, or save them to the DB
•     Introduce term_is_ancestor_of()
•     Introduce term_is_ancestor_of(); finish taxonomy support for wp_insert_category()
•     Introduce wp_is_mobile() and use it instead of $is_iphone global
•     Introduce wp_load_translations_early() which can be used before the locale is properly loaded in order to translate early error strings; internationalize setup-config.php — translators no longer have a reason to modify this file
•     Introduce ‘relative’ scheme to return only the paths for home_url, site, admin, network_, and get_ variants
•     Introduce WP_Theme->exists() to check if the queried theme actually exist; WP_Theme->exists() is a subset of errors(); a theme with errors may still exist, but a theme that does not exist has an error of theme_not_found; wp_get_theme() now returns false if the theme does not exist; improve scandir() and get_files() logic
•     Introduce WP_User::exists()
•     Lose EOF ?>; clean up EOF newline
•     Make get_post_custom() a wrapper of get_post_meta() so that it works when cache addition is suspended and to simplify it
•     Merge Press This inline styles into wp-admin.css
•     Move Options, Settings, and Transient functions from wp-includes/functions.php to wp-includes/option.php
•     New ‘wp_die_app_handler’ context in wp_die() for APP requests; introduces _scalar_wp_die_handler() as a generic handler that wraps die(), for use by plugins; move deprecated function to the end of the wp-app.php file (same as xmlrpc.php)
•     Provide a DB fallback for keys in wp_salt(); fall back when any secret is used more than once; change how we detect a localized ‘put your unique phrase here’–eliminate $wp_default_secret_key and introduce $wp_secret_key_default to be added during the localized build process, not by translators
•     Redirect bare category URLs for permalink structures starting with %category%
•     Reduce references to the $wp_rewrite global because it’s no longer used or a wrapper function can be used instead
•     Refactor WPDB::get_caller() into wp_debug_backtrace_summary() and improve the functionality to provide enhanced context and a standardised default pretty format
•     Remove show_last_update, include_last_update_time, and show_date code parameters from wp_list_categories(), wp_dropdown_categories()
•     Replace background image with CSS3 gradient in wp_die()
•     Repurpose wp_die() for ajax responses
•     Rewrite search_theme_directories() — better performance and allow for caching
•     Set post password cookies via an action in wp-login.php; retire wp-pass.php (one less root file); obey login ssl preferences for post password form submission
•     Split the main WP_Query posts query into two queries to avoid temp tables; leverage cache to avoid second query in persistent cache environments
•     TinyMCE: move the WordPress plugins styles to the theme’s stylesheet
•     Update add_permastruct() to allow more control over WP_Rewrite::generate_rewrite_rules()
•     Update switch_theme() to use wp_get_theme()
•     Update hierarchy for all hierarchical post types when deleting a parent post, not just for pages
•     Update hoverIntent to r6
•     Update jQuery imgAreaSelect plugin to 0.9.8
•     Update jQuery UI to 1.8.20
•     Update PHPDocs for wp_salt(), register_taxonomy_for_object_type(), wp_set_comment_status(), WP_Rewrite, rewrite endpoints, WP_Locale, wp_mime_type_icon(), mysql2date, get_taxonomy_labels(), WP_User::, register_post_status(), register_post_type()
•     Update PHPMailer to 5.2.1
•     Update Plupload to 1.5.4
•     Update SimplePie to 1.2.1
•     Update swfobject
•     Update TinyMCE to 3.4.9
•     Use get_taxonomies() instead of get_object_taxonomies() in the tag cloud widget
•     Use microtime() for cron locks
•     Use version_compare() when checking installed themes in the theme installer
•     When WordPress is in a subdirectory (home URL != site URL), let home/wp-admin and home/wp-login.php redirect to their proper locations
•     WordPress auto-detect RTL for the following locales: ar, ckb, fa_IR, he_IL, ug_CN, dv, fa_AF, ha, ps, uz_UZ, yi
•     WP_HTTP improvements
•     XML-RPC: Add support for Feature Images to the new wp.xxxPost apis
•     XML-RPC: Expose image_default_link_type, image_default_size, and image_default_align options
•     XML-RPC: Expose the post modified date (in blog TZ and GMT)
•     XML-RPC: Initial implementation of Taxonomy and Term APIs; implements wp.newTerm, wp.editTerm, wp.deleteTerm, wp.getTerm, wp.getTerms, wp.getTaxonomy and wp.getTaxonomies
•     XML-RPC: Introduce a date generation helper method to improve the dates returned over XMLRPC when we have a 0 date stored for drafts; improves the ability of clients to work with the new wp Post APIs
•     XML-RPC: Introduce new create,read,update and delete XMLRPC APIs for Posts, Pages and all Custom Post Types; introduces: wp.newPost, wp.editPost, wp.deletePost, wp.getPost, and wp.getPosts