Josh Green wrote in to point out this post by Jens Owen stating that the DRI project has updated the open source ATI Radeon 8500 (R200) drivers with full support for that hardware’s GPU. You may recall that back in early July the first snapshots of the driver became available, but without the ability to send transform, clipping, and lighting (TCL) operations to the GPU. As support for this hardware becomes more robust and the video hardware takes on more of the computations, users of the R200 cards should see improved performance.
Be aware that this is only an alpha release, and so may still have bugs that may cause instabilities in your system. You may download the binary snapshots from the snapshots page.