Here's the changelog:
Supports for NVIDIA PhysX acceleration on all GeForce 8-series, 9-series and 200-series GPUs with a minimum of 256MB dedicated graphics memory. Experience GPU PhysX acceleration in several full games and demos today by downloading the GeForce Power Pack. Supports AGEIA PhysX processors and software runtimes (no change to PPU driver support). Includes the latest PhysX runtimes used in the latest game titles. Supports the following NVIDIA PhysX runtime engines: 2.8.1, 2.8.0, 2.7.4, 2.7.3, 2.7.2, 2.7.1, 2.7.0, 2.6.x, 2.5.x, 2.4.x and 2.3.x Supports NVIDIA PhysX acceleration on GeForce via CUDA 2.0 for SDK versions 2.7.3, 2.7.2, 2.8.0 and 2.8.1 (requires graphics driver v177.81 or later). The PhysX control panel can be found in the Windows Start Menu under NVIDIA Corporation.