ive been keeping half an eye on that for the last few months, it looks very interesting
that idea has actualy been around for a while; offloading the physics calculations from the gpu and cpu and onto a seperate card, so it leaves more processing power free to improve other parts of the game.
nvidia are plannign to put one of sorts in their sli stuff in the next few months. Instead of 2 gfx cards, you can have a single gfx card and a physics processor.
Apparently though, this will not be as good as the ageia card. It will only be able to do things like particle and water effects, whereas the ageia allows full on collisions and stuff.