Intel's Zhenyu Wang has announced the creation of the "xvmc" branch in the xf86-video-intel driver. This new branch features code clean-ups relating to X-Video Motion Compensation (XvMC) and a new framework that will support greater hardware media decoding functionality in the future. The xvmc branch is designed to replace the earlier "xvmc-i915" branch. In addition, libIntelXvMC.so replaces libI915XvMC.so. Along with this new branch and framework, an XvMC option has been added to Intel's driver for the xorg.conf to disable this feature, which comes enabled by default.
XvMC is an X-Video extension for offloading video decoding to the graphics processor. The current Intel X.Org driver supports XvMC on the 915/945/G33 series. More information on this new Intel XvMC branch is available from the mailing list announcement
and the code can be checked out from its branch inside the xf86-video-intel git tree at FreeDesktop.org