Hi all,
I downloaded some of the HD trailers from the MS HD showcase, as well as a few similar
"tests" from other sites.

Using WMP 11 in Vista, with DXVA enabled in the preferences, works pretty well. 1080p video plays
back reasonably (no stuttering or pausing) well.

However, WMP in XP SP3, (with DXVA enabled in the preferences also) is a decidedly mixed bag.
It really isn't working that well, in fact the video's perform better and with less CPU if played back
in Graph Edit/GraphStudio.

1080p H.264 in MKV or MP4 play back extremely well (10% CPU) in MPC-HE, but it doesn't
work with WMV. IS it the Nvidia HW or driver that's the limitation? A little bit of info on the MPC-HE
home page mentions the fact that for Nvidia, only H.264 works, but for ATI owners, H264 & VC-1 work.
But the comment stops short of explaining exactly what the reason is.