I wasnt even aware that there was a 12.8 now. googling it, all it says is 12.8 did 2 things mostly:
1. Support for Windows 8, which was top priority for AMD as new users will use it
2. changed power consumption for most cards and fixed idle glitch for some computers, as well as add support for direct3d ssaa(fsaa).
idk if the drivers will work on a 7970m thoughaccording to this, it does support it