Could be good idea to ask Eric/Zhenyu about their Intel driver and Gallium. Will someone email them?
That would be one heck of a note (the motherboard I have lined up as a replacement is G41-based; I'd still be holding on to my HD5450 though, as nothing's wrong with it) to have Intel and AMD using the same driver core on the FOSS side of the GPU street; however, watch nVidia try to throw a spork-shaped spanner into the works...
latest r600g is much faster. Still not quite on par with classic mesa on my system, but close.
Unfortunately, the KWin effects are not working properly (very slow, like slideshow), and get automatically disabled after a while. They work fine with classic. But at least you can enable compositing now (a couple of days ago, it refused to do it).