For physics to become worth it, you have to have a dedicated GPU/PPU. You can do physics on the GPU alongside the actual graphics, but you'll sacrifice performance in the process. Aegea had it right in the first place. I'm not sure how far we are along to being able to properly support and use dedicated cards for physx, but when people are willing to go out and buy the hardware to make the game worthwhile, then it may happen. Of course that requires actual development from game developers, and then we get into the vicious cycle of "who will be first." The small stuff won't tax the cards too much currently, but I guarantee you that serious in-game physics will. You can quote me on that