AMD has released a new Catalyst 15.8 Beta Driver for Windows

NOTES

This driver is not intended for use on AMD products running in Apple Boot Camp platforms. Users of these platforms should contact their manufacturer for driver support.
When installing the AMD Catalyst Driver for Windows operating system, the user must be logged on as Administrator, or have Administrator rights to complete the installation of the AMD Catalyst Driver.
The AMD Catalyst 15.8 Beta Software Suite requires Windows 7 Service Pack 1 to be installed.
The AMD Catalyst 15.8 Beta Software Suite requires Microsoft .NET Framework 4.5 to be installed. Microsoft .NET Framework 4.5 is included in all AMD Catalyst driver packages.
AMD Eyefinity technology is designed to give gamers access to high display resolutions. As pixel count grows, the graphics "horsepower" required to drive the displays at a reasonable frame rate can increase dramatically. Depending on the game and system configuration, users may notice texture corruption and reduced frame rates when running games in multi-monitor Eyefinity modes.

  AMD Catalyst 15.8 Beta Driver for Windows