Hopefully they'll do a better job than last time they tried this: the galaxy S had a custom filesystem called RFS, in reality it was just fat32 with crappy journaling bolted on. It totally crippled the phone, causing a lengthly block every time a file was closed. It would also fight with the chips own wear levelling algorithms. It sucked. If you owned that phone and thought it sucked, with loads of UI lag, it was because of samsung's custom filesystem, which was also supposedly optimised for NAND.