Latest ATI patch enables HDR and AA in Elder Scrolls IV: Oblivion
 

Right now the ATI X1K architecture is the only architecture capable of allowing Floating Point HDR with AntiAliasing in Oblivion. We asked Terry Makedon when this fix will make its way into an official driver release on ATI.com and as of right now it looks like it will not be in the next Catalyst release (6.4). It is possible it could make it into Catalyst 6.5 but there is a chance it might not make it until 6.6. Therefore if you want to experience Oblivion with HDR and AA you'll need to use this Catalyst 6.3 driver until it is officially part of a new Catalyst release.