NGOHQ managed to grab the Catalyst 5.11b driver. They first thought it was Catalyst 5.12 beta but ATI emailed them to state these are in fact the Catalyst 5.11b drivers and not the upcoming Catalyst 5.12 drivers which will be launched in December.
The package includes the following:
* ATI Catalyst 5.11b Drivers with WHQL Certification for Windows XP/2000/x64/MCE * ATI Catalyst Control Center * ATI Control Panel * ATI MCE Control Panel. * WDMAll Radeon from 9500 and up are supported.
You can find them over NGO HQ