I successfully updated the firmware on the 80GB Intel X25-M that I normally use for my boot drive.
Prices have just dropped— if you have a Mac Pro, the X25-M is a great way to make it feel lightning fast as your boot and applications drive (always separate system and data, which is easily done on a Mac Pro).
You can get the updated firmware at Intel.
I’m currently booting off a 64GB Intel X25-E (“Extreme”) on both my Mac Pro and MacBook Pro (units on loan from Intel). The X25-E is really fast, but not noticeably different than the X25-M, because nearly all access to the system disk is read access. The X25-E is the same speed for reads, but shines at write speed (170MB/sec), about twice as fast as the 80MB/sec or so of the X25-M.