This quarter's Intel X.Org driver update really just brings a bunch of bug-fixes. From the release announcement, "The priority for this quarter has been simply to be unexciting and stabilise the driver further, seeking to capitalise upon the improvements elsewhere in the stack."
Notable bug-fixes shipping in this update is turning off relaxed fencing by default for older chipsets due to stability issues it has caused, an X.Org Server 1.7.7 build fix, KDE glitch fixes for Sandy Bridge hardware, among other changes.
Intel X.Org driver updates aren't particularly exciting anymore with a bulk of the interesting work taking place within the kernel DRM and Mesa components. Once Wayland fully takes over, the xf86-video-intel driver also becomes irrelevant.