Hi!
According to netkas, it must be supported on Mountain Lion since DP1.
In DP3 the ATI drivers changed a lot, even names of the Accelator kext & its bundles have changed.
So I would try to pick up the Extensions from ML DP1 / DP2 and try to install them on Snow Leopard or Lion.
The chance that they will work on Lion is ofcourse better, then it is for Snow Leopard, but Lion doesn't work on your CPU very well until now.
I would recommend you to try using only Framebuffer drivers from ML first, means ATISupport, ATIFramebuffer & ATI6000Controller
If it will give you resolution but no accerlation you can continue with trying ATIRadeonX3000 / AMDRadeonAccelerator (inlcuding those bundels & plugins mentioned
here)
I do not know if anyone else tried this yet, but I think there is some chance that it can work.
