Remember the MacBook SATA degrade, meaning affected MacBooks could only operate SATA at 1.5Gbit/s, potentially slowing down SSD MacBook Pros? It's been fixed in a somewhat grudging manner by Apple.
The MacBook Pro EFI firmware update 1.7: "allows drives to use transfer rates greater than 1.5Gbps, Apple has not qualified or offered these drives for Mac notebooks and their use is unsupported."
Apple goes on to say: "All previous and current Apple portables with a SATA drive interface include a SATA 1.5Gbps hard drive," and doesn't mention SSD use.
It was thought that affected MacBooks with SSDs would not run as fast as they might. This obstacle to their performance appears to have been removed. Some comments on the MacRumours forum took a negative tack, suggesting that running SATA at the faster 3Gbit/s speed could drain batteries faster.
The firmware update is 3.35MB in size and requires Mac OS X version 10.5.7. ®