it would be nice to see a revival of the OpenML standard. Modern graphics cards do not only provide 3D graphics acceleration, but video acceleration as well. Microsoft offers the non-portable DirectX Video Acceleration (DXVA) and DirectShow APIs.
Intel does work on a video decoding acceleration interface for X11 which is called vaAPI (http://www.freedesktop.org/wiki/Software/vaapi). Eventually, the efforts can be merged to allow fully portable video applications in the near future?
nVidia has not committed to help yet, but their Linux driver team has to deal with video acceleration of the GeForce 8 GPU series.
I feel that we can work together to lift this one, seeing the work already done on this issue.
Of course, we need the graphics hardware manufacturers nVidia, ATI, and Intel to specify the features which will be accelerated. It should be possible to support DXVA and OpenML VA at the same time easily, because I don't think DXVA is going away anytime soon. This is similar to OpenGL and Direct3D, the industry already does support two APIs successfully.