This question was asked nearly six months ago (elsewhere) and was replied to by Mike Gilbert (tdragger) in one of his blog entries.
The short story is that they (ACES) looked at the hardware, evaluated what it might offer FS, and decided that at the present time it would be of little or no value whatsoever, and would require a lot of extra code just to obtain that tiny bit of gain.
Just for the above reasons it would make no sense to invest time and effort.