ATI has just posted the official 6.3 Catalyst drivers to their site
They have also integrated a new "Anti-Leeching" system into their website, so unfortunately you have to visit their site to find the appropriate package. We can"t even link to the release notes directly. Again, those of you looking for a complete driver package without the .NET based control package are out of luck. There is however a standalone driver package, which only contains the 6.3 drivers but no control set for Windows.