Totallymaxed, if you want to test VDPAU on the Acer Revo, the latest XBMC Live CD supports it out of the box
Just boot the CD, Choose Nvidia in the startup, and when booted set decoder to VDPAU.
Insert a USB drive with x264 content and se the CPU use in a terminal.
I have tested this on one of my MD's with a GF8600GT card and it works
CPU is at 2-8% load while watching 1080p content.