Not sure if I'm allowed to ask Mac questions here, but does anyone know if the 4800 series is destined for the Mac anytime soon? I couldn't find anything via Google.
Sure you can ask MAC questions, whether you'll get good MAC answers is another story.
Biggest issue is Apple's certification process, most new GPU solutions take a while to be approved for being put into a MAC, it's usually about 4-6 months, and sometimes the companies don't bother to apply. Writing the MAC drivers is the only thing keeping you from just slapping one in the rig on your own.