Wow that was quick, WordPress 3.8 Beta 1  has been released and the final release is targeted for Thursday, 12th December 2013!
I am looking forward to the new admin UI!
- The new admin design, especially the responsive aspect of it. Try it out on different devices and browsers, see how it goes, especially the more complex pages like widgets or seldom-looked-at-places like Press This. Color schemes, which you can change on your profile, have also been spruced up.
- The dashboard homepage has been refreshed, poke and prod it.
- Choosing themes under Appearance is completely different, try to break it however possible.
- There’s a new default theme, Twenty Fourteen.
- Over 250 issues closed already .
Download: WordPress 3.8 Beta 1