Nvidia may be promoting PhysX as a way to sell more GeForces, but the company hasn't forgotten about the physics application programming interface's other uses. In fact, Nvidia has announced that it's struck a deal with Sony to give PlayStation 3 game developers free access to the PhysX software development kit.
As part of the license agreement, the PhysX SDK (in its binary form) is available to "registered PS3 developers for free download and use on the SCEI Developer Network." Nvidia points out that the free SDK includes both the PhysX application programming interface and a "robust physics engine."
If that sounds familiar, it's because Ageia made a similar announcement almost exactly three years ago, long before the Nvidia acquisition. Back then, Ageia noted that the PlayStation 3 version of the PhysX engine ran on the Cell processor and not the console's GPU. The PS3 does have an Nvidia graphics chip, but it's based on a pre-GeForce 8 architecture that presumably lacks CUDA or PhysX support.
The binary SDK has been freely available to PC developers for some time now, too. Folks who want the actual source code have to cough up $50,000 per application.