The Ubuntu-X testers have been feverishly testing their 2.6.33-pulled Nouveau DRM on the Linux 2.6.32 kernel along with their KMS-supported xf86-video-nouveau DDX driver. Canonical's Bryce Harrington describes this Nouveau stack as being "nearly ready" for Lucid and is requesting a final test among those interested in the open-source NVIDIA graphics hardware support. This is only for 2D/video and kernel mode-setting support, but the Gallium3D driver for providing OpenGL acceleration isn't going to be deployed, so users are left with the software rasterizer.
If you are interested in testing out Ubuntu 10.04's Nouveau stack you can do so by following this call for testing thread and checking out the Nouveau evaluation Wiki page.
Ubuntu developers are interested in knowing whether the system boots, if VT switching functions, whether the default resolution that is mode-set is correct, the resolution listing is correct, whether RandR-driven screen inverting and rotation works, can movies play with Nouveau in Totem, if Adobe Flash correctly works, if software 3D will not crash the X Server, and lastly is if suspend-and-resume/hibernation works accordingly.