AMD just realeased a new version of their proprietary graphics driver fglrx. While usually they only introduce new bugs every months while the really interesting stuff is happening within the open source radeon driver, this month there are also some interesting things in fglrx.
Not that it would excite any of the existing radeon users, since they have got that stuff for months, but now fglrx also supports Xrandr 1.2 and accelerated 2D rendering through Xrender.
in order to enable this, add the following to the Video Device Section of your xorg.conf:
Option "Textured2D" Option "EnableRandR12" Option "TexturedXrender"
Textured2D is AMDs acceleration architecture for primitive drawing, similar to EXA in the open source world and is required for the Xrender Acceleration.
Although 2D is just as good as with the OSS drivers now, the texture_from_pixmap extension is still slow and so is scrolling in compiz, therefore I would still recommend the OSS drivers for compiz.