"The first release candidate for Gimp 2.4 has been released. Among the many improvements in this upcoming version, new version of several of the most used tools and an improved interface with redesigned menus and new icons for tools. This version doesn't have support for images with more than 8 bit per color channel, the support will come with the version 2.6 of the Gimp."
http://www.gimp.org/
If you want to help by testing this release candidate, you can grab the source code from ftp.gimp.org. The release notes for the development releases still apply.