Although I'm happy to see regular updates to the r600g driver, I hope someone will eventually look into Minecraft performance, it's been somewhat poor on my 4850 and 5850 radeons
Not in my experience. It runs fine here on pretty much any nvidia card I own, including the fairly underpowered Geforce 9500GT (and MC runs a lot better with Catalyst compared to Mesa using the same GPU). I've been told that Minecraft uses almost exclusively immediate mode OpenGL, which I assumed was just not a very optimised part of the Mesa driver (becuase who uses immediate mode nowadays? ), so if that's the reason it's slow I guess that makes sense.