Last week AMD introduced the Catalyst 10.3a drivers, and this week they've published the Catalyst 10.3 WHQL drivers, which you can download over here. This may sound a bit confusing, but the non-WHQL drivers that were released last week are newer than this release, so people who want the best performance may want to stick with the Catalyst 10.3a drivers.
The Catalyst 10.3 drivers promise performance gains in 3DMark Vantage, Aliens vs. Predator, Battleforge, CoD: World at War, Company of Heroes, Crysis, Crysis Warhead, Devil May Cry 4, DiRT 2, Enemy Territory: Quake Wars, Far Cry 2, Left 4 Dead, Left 4 Dead 2, S.T.A.L.K.E.R. Call of Pripyat and Cleary Sky, Resident Evil 5, H.A.W.X, Unigine Tropics, World in Conflict and Wolfenstein. The promised performance boosts generally range from 2 percent to 6 percent, but in some specific cases the gains can be as high as 15-30 percent.
Additionally, there are also some new features such as ATI Eyefinity enhancements and support for 3D stereoscopic glasses. You can read the full changelog below: