AMD has published the Catalyst 12.4 WHQL driver, you can download it over here.
Here's a list of the new features:
Windows XP support for the AMD Radeon HD 7900 Series, AMD Radeon HD 7800, and AMD Radeon HD 7700 Series
In addition to Windows 7 and Windows Vista support, Catalyst 12.4 now also introduces Windows XP (64-bit/32-bit) support for the AMD Radeon HD 7900, AMD Radeon HD 7800, and AMD Radeon HD 7700 Series
Super Sampling Anti-Aliasing: Level of Detail (LOD) Image Quality enhancements:
Supported on the AMD Radeon HD 7900, AMD Radeon HD 7800, and AMD Radeon HD 7700 Series
LOD Image quality enhancements have been improved when enabling Super Sample Anti-Aliasing and Adaptive Anti-Aliasing through the AMD Catalyst Control Center for DirectX 10 and DirectX 11 applications.
Applications must support in game Anti-Aliasing for the feature to work (Forced on Anti-Aliasing through the Catalyst Control Center is not supported for DirectX 10 and DirectX 11 applications)