NVIDIA announced that all GeForce 6 and GeForce 7 GPUs will eventually (when drivers and software are available) support H.264 decode acceleration for all the way up to 1080p videos. Obviously the faster the GPU (mainly the more ALUs and the higher the clock speed), the more that can be offloaded from the CPU onto the GPU.
Enabling hardware acceleration offloaded a good hunk of the decoding task onto the Geforce 6600GT, reducing CPU utilization to around 50% or less
While they are definitely lagging behind ATI in H.264 decode acceleration, at least NVIDIA has finally provided us with a working demo of the technology and they have also committed to us that it will work on all GeForce 6 and 7 GPUs (AGP and PCIe).
http://www.anandtech.com/tradeshows/...spx?i=2665&p=2