Was a bit curious so I just typed in Ati Catalyst 9.6 in google and it popped up, 2 forums, one Guru3D.com, had a topic on it with a link for Vista x86/x64. Here it is:
Who knows really. No release notes have been released. From what I have read, and this is just a guess, performance gains will probably be minimal if any. (Again, I am guessing), I think the focus of ATI right now is making sure any and all bugs are worked out for the retail release of Windows 7. Atleast that is what I have read. Who knows if any of it is true though. I suppose that is what every developer is doing right now with the RC, just polishing their drivers and so forth. If you want to hear of some really far out speculation, I read that they weren't going to be doing any serious optimization of their drivers until after the retail release of Windows 7, as in this time next year or so. Seems far out there to me, but that is the talk I have read. Wouldn't put to much faith in that though if it were me.