I'm suspicious about the future success of the hardware.
Traditionally, hardware with dedicated physical inputs and outputs seem to be successful. Sounds cards, video cards, etc.
Cards the assist with processing tend to fail. Anyone remember those MPEG movie cards? They seemed to be the next big thing, and people bought them, but they're long dead. Now, CPUs can easily handle the load of the 2D video.
The PhysX card is similar, in that it will only assist the CPU and not output anything. More powerful CPUs will just take over. Once you've added the processing power of the new card to an existing CPU, there's really no need for it. Then, it's just the software...