Here's a list of the new features:
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)
Morphological Anti-Aliasing (MLAA): Significant performance enhancements:
Supported on the AMD Radeon HD 7900, AMD Radeon HD 7800, AMD Radeon HD 7700 Series, AMD Radeon HD 6000 Series, and AMD Radeon HD 5000 Series MLAA now operates up to 80% faster than previous versions
Texture filtering quality improvements:Supported on the AMD Radeon HD 7900, AMD Radeon HD 7800, and AMD Radeon HD 7700 Series Improvements have been made to the texture filtering algorithm (for both DirectX9 and DirectX10/DirectX11 applications) to increase the quality of rendered textures, with no impact to performance