The initial F2FS benchmark results were impressive against the established Linux file-systems like EXT4 and Btrfs. F2FS is just designed to run on flash-based storage mediums and is designed around the characteristics of NAND flash memory. If you're not yet familiar with Samsung's Flash-Friendly File-System, there's been dozens of Phoronix articles covering its performance, its new features, etc.
For those not actively monitoring the Linux kernel mailing list, more performance improvements are abound for F2FS. Among other patches still outstanding, Jaegeuk Kim of Samsung has more performance improvements, such as with this patch from yesterday.
The latest patch improves the write performance under workloads where fsync() is called frequently. The random write performance with this patch is reportedly up by about another 10%. This patch along with other improvements should be seen within the Linux 3.14 kernel that will soon be entering its official development stage.
Features still being planned/developed for F2FS include offline file-system checking, offline resizing, improved direct I/O, data de-duplication support, transparent compression support, removable device support, and atomic operations. Also likely blocking Samsung from using F2FS yet in any consumer devices is the lack of a Windows F2FS file-system driver, although it's been talked about as a future work item.