A search round the driver page reveals that Linux drivers are still available for the FireGL series of pro cards, and as the latest Radeon cards are based on FireGL technology, Radeon 8500 or later are supported by the driver. If you download the latest driver rpm for "FireGL X1, FireGL X1 128MB, FireGL Z1, FireGL 8800, FireGL 8700" then the package description lists "ATI Radeon 8500, 9700, Mobility M9 and the FireGL 8700/8800, E1, Z1/X1" as supported cards. Hopefully ATI will continue to produce updated versions of this driver, with new extensions, support for new versions of glibc and new versions of XFree86. It would be much better if they could list this driver in the standard section so that users would know it was available and supported Radeon cards.
I am using this driver currently with my Radeon 9000 Pro, and have had excellent results.
I'll post how it worked out when I have time.