Linus Torvalds announced last night the release of Linux 2.6.30-rc1 with the merge window for it now being closed. What this kernel brings is, well, support for more file-systems. If the new EXT4 and Btrfs file-systems are not enough for you, the Linux 2.6.30 supports two more file-systems. No, these new file-systems aren't Reiser4 and ZFS (or Microsoft's exFS) or anything like that, but NILFS2 and EXOFS. NILF2 is described by Linus as "another log-structured filesystem that does snapshotting" while EXOFS (previously known as OSDFS) is a bit more complicated as it's implemented on top of an external object store. With the Linux 2.6.30 kernel, there are now about four dozen file-systems supported by the Linux kernel.
Besides new file-systems and improvements to other file-systems (including EXT3 and Btrfs), there are various new drivers and updates to others. However, none of them are particularly interesting. One item worth noting is that the Linux 2.6.30 kernel does support the AMD SB800 Southbridges for SMBus, etc. There is no NVIDIA or ATI kernel mode-setting support in the mainline kernel yet or any significant additions to either the Graphics Execution Manager or KMS in this release, but the ATI R600/700 DRM support has entered the Linux 2.6.30 kernel.
The Linux 2.6.30-rc1 kernel release announcement from Linus can be read here.