Phoronix: New Radeon Driver Supports Mac Mini
Alex Deucher has released the xf86-video-ati 6.7.194 RC driver. This open-source Radeon driver has initial support for Apples's Mac Mini, fixed Xv crasher, a number of LVDS fixes, and external TMDS should work again.
But "ati" isn't the new radeon driver. I think many people think of "radeonhd" with this heading.
That could only be the PPC part as the X86 ones use Intel onboard video.