Overall the 10.5 had minimal new features or fixes for Eyefinity users:
ATI Overdrive - Enhanced to deliver full support for over-clocking functionality on supported ATI Radeon HD graphics accelerators connected to multiple display configurations
Catalyst Control Center - Fixed issue where the CCC now remembers the position of the fourth monitor in the Eyefinity group5
Battlefield 2: Bad Company - Fixed issue with map load time.
Mass Effect 2 - Alt-Tabbing to the desktop no longer causes the display to go blank.
Source:AMD
