What Intel defines as this quarter's package is the xf86-video-intel 2.15.0 DDX, Mesa 7.10.2, libdrm 2.4.25, Linux 2.6.38 kernel + some out-of-tree patches, libva 0.12, and X.Org Server 1.10.
Most of the work going into the Intel Linux driver this quarter are bug-fixes and further refinements to the Sandy Bridge hardware support. New though is VC-1 decoding for Sandy Bridge, H.264 encoding support, power saving support, and Mesa performance improvements (Intel cites our article for the SNB performance improvement).
It's interesting that Intel is citing the Sandy Bridge VA-API H.264 encoding support as being a 2011Q1 package feature when it's living in a libva code branch, has only been out for a number of days, and there really isn't much in the way of multimedia applications yet taking advantage of the VA-API encoding interface.
Bugged up in this version is Sandy Bridge frame-buffer compression not always working as well as suspend-and-resume sometimes resulting in hangs.
The 2011Q1 package information can be found at IntelLinuxGraphics.org.