The team at WordPress talk about the new 3.6 release in their Beta 1 post:
“We’ve been working for nearly three months and have completed all the features that are slated for this release. This is a bit of a change from the betas of previous release cycles. I felt very strongly that we shouldn’t release a beta if we were still working on completing the main features. This beta is actually a beta, not an alpha that we’re calling a beta. If you are a WordPress plugin or theme developer, or a WordPress hosting provider, you should absolutely start testing your code against this new version now. More bugs will be fixed, and some of the features will get polished, but we’re not going to shove in some big new feature. We’re ready for you to test it, so jump in there! The more you test the beta, the more stable our release candidates and our final release will be.”
They also explain the delay in releasing Beta 2…
“The longer-than-usual delay between beta 1 and beta 2 was due to poor user testing results with the Post Formats UI. Beta 2 contains a modified approach for format choosing and switching, which has done well in user testing. We’ve also made the Post Formats UI hide-able via Screen Options, and set a reasonable default based on what your theme supports.”
There’s another update with the release of Beta 3:
“Beta 3 contains about a hundred changes, including improvements to the image Post Format flow (yay, drag-and-drop image upload!), a more polished revision comparison screen, and a more quote-like quote format for Twenty Thirteen.
As a bonus, we now have oEmbed support for the popular music-streaming services Rdio and Spotify (the latter of which kindly created an oEmbed endpoint a mere 24 hours after we lamented their lack of one).”
Here’s the overview of what’s new in 3.6:
- Post Formats: Post Formats now have their own UI, and theme authors have access to templating functions to access the structured data.
- Twenty Thirteen: We’re shipping this year’s default theme in our first release of the year. Twenty Thirteen is an opinionated, color-rich, blog-centric theme that makes full use of the new Post Formats support.
- Audio/Video: You can embed audio and video files into your posts without relying on a plugin or a third party media hosting service.
- Autosave: Posts are now autosaved locally. If your browser crashes, your computer dies, or the server goes offline as you’re saving, you won’t lose the your post.
- Post Locking: See when someone is currently editing a post, and kick them out of it if they fall asleep at the keyboard.
- Nav Menus: Nav menus have been simplified with an accordion-based UI, and a separate tab for bulk-assigning menus to locations.
- Revisions: The all-new revisions UI features avatars, a slider that “scrubs” through history, and two-slider range comparisons.