In an almost overlooked note on the Android Developers Blog, Tim Bray lets us know that starting with the Nexus S and Gingerbread, some Android devices will be moving from the YAFFS file system to the ext4 file system. This is going to bring a big boost in input and output file operations, and explains some of the amazing speed improvements we're already seeing on the Nexus S.
Two things to mention here -- the increase in speed comes with a cost, and not all current (or new) devices will see this change. The lifespan of the media will be reduced by using the ext4 file system, but modern solid state memory should still last for quite a few years, so I don't see a serious problem with it. The other issue is which phones will see this boost. I've a gut feeling that this is reserved for only new devices with big internal memory space, like the Nexus S, that have a controller that can use it. I wouldn't count on your current phone to get this change -- at least officially -- but hopefully manufacturers will make sure their new devices meet the needed specs.
Not sure what exactly an ext4 file system is, or want to talk about these changes and what they might mean to Android? Get in the Gingerbread forums and suss it all out. Feed your geek. [Android Developer blog via Thunk.org] Thanks Sean!