The set of 42 patches posted yesterday are to merge new H.264 encoding APIs from their staging branch. Going back to late 2011 was a VA-API proposal for a new video post-processing entry point along with other extensions. Intel's Open-Source Technology Center has been building upon that earlier work and refined the APIs to add support for MPEG-2 encoding too.
Up to this point VA-API has basically been about video decode acceleration, but now video encoding support is being spiced up by Intel to benefit their latest generations of Intel hardware running Linux.
For those wishing to dig into deeper detail about these new Video Acceleration API patches, the new patch series begins here on the libva mailing list.