I found this snippet of information to be quite interesting:
Q. The current PureVideo decoder on the NVIDIA site is dated June 28th 2006. Will there be a new PureVideo release at the end of March?
Starting last year, we started working with all of the top-tier video decoders to enable PureVideo directly into their decoders. Third-party decoders and movie players such as Cyberlink PowerDVD and Intervideo WinDVD can now be used for playing movies using our PureVideo technologies. In fact, this is a key priority for us since it gets the features and performance of PureVideo to the masses.