That project ended up being abandoned prior to completion, but David Airlie at Red Hat managed to develop X-Video GLAMOR acceleration in just one days time. David's experimental QEMU 3D acceleration is likely to use GLAMOR and so he spent a day hacking in X-Video acceleration support.
David wrote on his blog, "Xv works for YV12 planar videos, I suspect to do packed video support I'd need a GL extension to expose the hw formats for doing packed video, this probably wouldn't be a major extension and maybe someone might do it sometime. The code supports, brightness, contrast, hue and saturation controls using the code ported from the radeon driver. I've tested it with mplayer on evergreen card of some variant, and it seems to work fine with the one video I used :-) "