Underneath these updated desktops will be X Server 1.6, EXT4 file-system (or optionally Btrfs), the Linux 2.6.29 kernel, and GCC 4.4.
An updated package that will also make its way into Fedora 11 is Thunderbird 3. This updated Mozilla mail client brings a revised user-interface, easier configuration of mail options, a new add-on manager, faster content searching, G-Mail IMAP support, better extensibility, and architectural cleanups. The latest version of Thunderbird 3.0 is Beta 2, but the targeted release date for a stable version is unknown at this time.
More information on the Thunderbird 3 support in Fedora 11 can be found on the Fedora Project Wiki. Fedora 11 will also be upgrading to Firefox 3.1.