For end-users, simply put, color tiling is able to result in increased graphics performance. KMS color tiling was previously enabled in Mesa by default for pre-R600 (up through the Radeon X1000 "R500" series) previously, but the R600+ color tiling support was disabled by default and had to be enabled via a xorg.conf option. It was more than a year ago that R600/700 tiling support originally came to the xf86-video-ati and Mesa drivers while it was commited in August. It wasn't until earlier this year that color tiling support was even committed for the Radeon HD 5000 series and newer.
Thanks to today's Git commit, KMS color tiling is now the default for the Radeon HD 2000/3000/4000/5000/6000/6900 series graphics processors, including Fusion hardware. This will officially be released in the next xf86-video-ati X.Org driver release and will be found in Fedora 16, Ubuntu 11.10, and other updated Linux distributions.
See our recent Radeon Gallium3D benchmarks to see where the performance is at, including when color tiling is enabled along with disabling swap buffer waits.
For now this enabling of color tiling is limited to 1D tiling, which isn't as great as 2D tiling, but there are some bugs outstanding. When the 2D tiling for R600+ is fixed up, there will be more gains to experience.
This announcement is also coming on the heals of AMD's Llano Fusion Linux launch. There will be results on Phoronix tomorrow, but not without jumping through hurdles to simply gain remote access.