It is being reported that OS X 10.8.3 beta has ATI Tahiti 7000 drivers support and can be found in the system profiler. This could very well mean that Mountain Lion is ready for an imminent Mac Pro refresh. In addition, the new iMacs are said to have Nvidia graphics, so this support isn't mean for those--no current Macs has these graphic chips, so it's good news for those hardcore users that need extra muscle and have been holding out.