Doesn't Physx already run on the CPU if it is needed for the game (ie not Hardware Physx like in the Arkham series)
Yes it run on cpu for other platform ever since it was released under ageia. It's nothing new if that is all it is. Now with opencl and direct compute, I don't really see much compelling reason to use physx. Other option can run on any gpu so there is no need for special considerations and it can do most of same things a far as gaming goes.