It might interest some list members that it seems vdpau is coming to VLC 1.1 - which might not be too far away.
http://www.jbkempf.com/blog/post/2010/01/31/VLC-and-GPU-decoding-on-linux-aka-Re%3A-Welcome-to-the-Thicket
{Sorry if this is old news however I've not seen any one reference this in the context of mythtv}