Check out the video below to see the changes that you would get with WordPress 3.9.
3.9 introduces many updates that target the media experience. This includes enhancements to image editing, gallery management, audio play list management and much more.
Ultimatum framework Support for WordPress 3.9
If you are Ultimatum framework user for WordPress then no worries, everything works fine with 3.9 and development team at Ultimatum framework has given green signal for core update from 3.8 to 3.9
If you have been waiting for WordPress 3.9 Updates we are glad to say after testing it to each bit Ultimatum at current version is flawlessly working with WordPress 3.9
We had some issues with WordPress 3.9 on some of our test servers which we found was not about Ultimatum but a WordPress bug. We have reported the bug to WP community which they thought was only a i18n issue but with php 5.4 servers that small code made media manager of WordPress fail on post/theme/plugin levels.
Due to that issue we have warned not to update yet but we have the solution and you can update to WP 3.9 safely but if you have any issues after update like Connection Reset errors etc please see:
All in all 3.9 looks promising and not that buggy as some one of the older version.