Making the F2FS file-system updates interesting for this next Linux kernel release are new features and performance improvements. Enhancements/features for F2FS in the 3.12 kernel include inline xattrs, sysfs support to control GCs explicitly, and a proc entry to show the current segment usage information. The performance work comes down to improvements in worst case scenarios for GC/SSR. Aside from this work, there's also F2FS bug-fixes.
More details on these updates to the Linux Flash Friendly File-System can be found via the mailing list pull request by Samsung's Jaegeuk Kim.