Submitted to the mailing list over the weekend was a patch by Carl-Philip Haensch that implements support for Anisotropic Filtering (AF) in the ATI/AMD R600 Gallium3D driver.
This relatively small patch now makes it possible to utilize this method for enhancing the image quality of textures.
The R600 Gallium3D driver supports hardware from the Radeon HD 2000 series through the latest Radeon HD 6000 series, including the new AMD Fusion parts as well.
The patch in question can be found on the Mesa mailing list
Along similar lines, to be worked on this summer
as part of Google Summer of Code is support for Morphological Anti-Aliasing (MLAA).