HDCP support
The biggest feature is definitely the inclusion of HDCP. While all the graphic chip manufacturers eagerly mentioned that their chips are HDCP capable, very few card manufacturers have decided to include the necessary chip to enable such a use. Even when that was the case, the cards were not top of the line, but were aimed at HTPC users.
The GeForce 7950GX2 has full HDCP support, which enables the user to watch Blu-Ray and HD DVD content. Nonetheless there is no HDMI connector on the card, as the Audio would need to be routed through the graphic card using a specific chip. To keep costs down, this was not included.
By having HDCP support, the high definition content of Blu-Ray and HD-DVD can be played back at up to 1080p resolution. This is were the H.264 acceleration comes in handy, as it takes the load of the CPU and does all the work on the GPU.