Nouveau's Maarten Maathuis has announced on the dri-devel mailing list that he has imported his initial kernel mode-setting code for the (NV50/G80) GeForce 8 series. This kernel mode-setting code isn't using RandR 1.2 cloning and lacks support for LVDS panels with no DDC, no FBCON, no output/connector properties.
Next on Maarten's kernel mode-setting road-map is cleaning up the Nouveau DRI locking code and some other minor fixes. This KMS support has been committed to master and here is the patch that adds the support to the xf86-video-nouveau driver. Kernel mode-setting is not yet used by default but must be setup manually.
For those not up to speed on kernel mode-setting, it's one of the exciting up-and-coming technologies occurring in the X.Org / kernel spectrum. Moving the video mode-setting code into the kernel allows for a flicker-free boot process, the possibility of a Linux "BSOD" (graphical error message) support, clean switching between virtual terminals, and many other advantages. For more information, read our Preview of Kernel Mode-Setting.
The Intel driver has been the driver with the best level of kernel mode-setting support so far and it even ships with Fedora 9. There is also some Radeon kernel mode-setting code written by Jerome Glisse and was first published last December. However, the kernel mode-setting code for ATI Radeon cards has yet to hit the master development branch.