This multiple ring buffer support is needed to support H.264 decoding using libva for VA-API. Those interested in testing it out should just have to apply Zou's patch against drm-intel-next and then use the i965_H264 branch of the library needed for the Video Acceleration API. The VA-API version of MPlayer is also needed for support.
The patch can be found on Intel's mailing list. Hopefully it will be merged into the Linux 2.6.35 kernel to provide a better video experience for those using Intel Clarkdale/Arrandale systems.