Apart of all the little tweaks and fixes there are also a bunch of very useful feature coming along with this version:
Experienced users will appreciate the new drag-and-drop uploader, hover menus for the navigation, the new toolbar, improved co-editing support, and the new Tumblr importer. We’ve also been thinking a ton about what the WordPress experience is like for people completely new to the software. Version 3.3 has significant improvements there with pointer tips for new features included in each update, a friendly welcome message for first-time users, and revamped help tabs throughout the interface. Finally we’ve improved the dashboard experience on the iPad and other tablets with better touch support.
There is a ton of candy for developers as well. I’d recommend starting your exploration with the new editor API, new jQuery version, better ways to hook into the help screens, more performant post-slug-only permalinks, and of course the entire list of improvements on the Codex and in Trac.
Of course we updated our documentation to the newest version and also the WordPress Syntax Mode for Coda got an update.
Please have a look at our Function, Action and Filter index for a quick overview and see the list of some of the new and deprecated functions below.
- _wp_footer_scripts – Private, for use in *_footer_scripts hooks
- check_theme_switched – Checks if a theme has been changed and runs ‘after_switch_theme’ hook on the next WP load
- print_late_styles – Prints the styles that were queued too late for the HTML head.
Meta data related
- delete_metadata_by_mid – Delete meta data by meta ID
- delete_post_thumbnail – Removes a post thumbnail.
- get_metadata_by_mid – Get meta data by meta ID
- metadata_exists – Determine if a meta key is set for a given object
- register_meta – Register meta key
- update_metadata_by_mid – Update meta data by meta ID
Admin bar related
- wp_admin_bar_add_secondary_groups – Add secondary menus.
- wp_admin_bar_my_account_item – Add the "My Account" item.
- wp_admin_bar_search_menu – Add search form.
- wp_admin_bar_site_menu – Add the "Site Name" menu.
- wp_admin_bar_wp_menu – Add the WordPress logo menu.
- is_main_query – Is the query the main query?
- wp_cache_decr – Decrement numeric cache item’s value
- wp_cache_incr – Increment numeric cache item’s value
- wp_editor – Renders an editor.
- wp_no_robots – Display a noindex meta tag.
- wp_trim_words – Trims text to a certain number of words.