Release candidate 2 of WordPress 3.8 is now available for download. This is the last pre-release, and we expect it to be effectively identical to whatâ€™s officially released to the public on Thursday.
This means if you are a plugin or theme developer, start your engines! (If theyâ€™re not going already.) Lots of admin code has changed so itâ€™s especially important to see if your plugin works well within the new admin design and layout, and update the â€œTested up to:â€ part of your plugin readme.txt.
Read more @ http://wordpress.org/news/2013/12/3-8-rc2/