Neither have I. Maybe Apple will blaze a trail in that arena.
EDIT:Found this link. It has a decent list of the mobile GPU solutions. Some even have power requirements listed.
Well, again, it's no longer going to be necessary. As long as Apple does use the updated GPU's (like the GeForce 8600 or ATI's mobile X2600), they will be able to offer that level of performance without any extraordinary effort.
The 8600 is already known to be available in some upcoming 14 and 15" notebooks from Asus, so it should be possible for Apple to use (or use the ATI equivalent).