The kernel team started out by back-porting the Nouveau DRM to the 2.6.32 kernel, but in the end they decided to pull in the entire 2.6.33 DRM for better graphics support, rather than switching over the entire kernel to the 2.6.33 code-base.
Now there's a possibility we could see the same sort of back-porting occur with the X.Org Server. The Ubuntu X team has already brought some of the udev input changes over to their X.Org Server 1.7.x code-base due to the deprecation of the FreeDesktop.org HAL (Hardware Abstraction Layer) in Ubuntu 10.04. Timo Aaltonen has now published a patch to Ubuntu-X that brings most of the X Server 1.8 features back atop their 1.7 server. This includes support for the xorg.conf.d, the new input class attributes, proper udev support (the currently back-ported support isn't the same as upstream), and various other patches that address different bugs.
As Timo states in his mailing list message:
Well, if this could be shipped with squeeze/lucid, it would allow us to get in sync with upstream, and not ship a "temporary" udev hotplug solution on a long term release with different documentation than the rest of the world (and us in six months).
There's also other technical benefits to this back-porting, but it's rather unlikely these new X.Org Server patches will be pulled into Ubuntu Lucid this late into the development cycle with the official release being only one month out. Meanwhile, the official release of X Server 1.8 is due out in just a few days and it (or ideally, X Server 1.9) will find its way into Ubuntu 10.10.