12.8 is working perfectly on my HD7950 DCII. I'm seeing performance gains in Max Payne 3, Future Soldier, Skyrim and Witcher 2. Plus the problem of that nasty AMD codec stopping windows 7 from starting also stopped.
CPU + Mobo :: Core i5 3570K + Asus Maximus V Formula
CPU Cooler :: Corsair H80
GFX :: Asus HD7950 Direct CUII + Sapphire HD7950 Dual-X
RAM :: GSkill TridentX 2400 CL10 16GB
Storage :: Corsair SSD - 60GB + Seagate Baracuda - 1TB
PSU :: Corsair AX 850
Cabinet :: Silverstone Raven RV03
Keyboard + Mouse :: Logitech G110 + Razer DeathAdder
Audio :: JBL Creature III + Razer Megalodon 7.1
Display :: AOC e2352Phz