NVIDIA plans on launching patches on August 12 to enable its GeForce 8-series and later graphics cards to run PhysX physics modeling on the GPU. Presumably an NDA about this expired today, as there are new previews of this new PhysX support on several sites, offering background, hands-on impressions, and benchmarks. You can find these previews on Custom PC, Elite Bastards, HotHardware, and The Tech Report. Here's a summary of the situation from the latter preview:

On August 12, Nvidia will release new graphics drivers that will allow owners of most GeForce 8, GeForce 9, and GeForce GTX 200-series cards to use PhysX acceleration without spending a dime. Along with the drivers will come a downloadable PhysX software pack containing free Unreal Tournament 3 maps, the full version of NetDevil's Warmonger, a couple of Nvidia demos, and sneak peeks at Object Software's Metal Knight Zero and Nurien Software's Nurien social-networking service. Nvidia provided us with early access to the pack, and we've been testing it over the past couple of days.