It's not like it was kept a secret til the day it was added. It was common knowledge for a very long time before that. As a matter of fact, once it became blatantly obvious there was a high demand for hd content, neglecting to include h264 would've been idiotic.
All that aside, you should have a look at the following thread titled VDPAU testing tool
. The results to tons of video cards have been posted there and it should help you figure out what best suits your needs.