6950 is fine. probably no need to flash bios to 6970 for just 1080p, all games will run great. you have no worries, there will be no noticeable bottleneck. If you went to an i5 2500k sure you will see an improvement in FPS if your looking at the pure numbers, but games wont feel or look any noticeable difference.
Actually i play SC2 all the time, and any some other fps games rarely. SC2 needs a better cpu for higher fps, but i'm just trying to get the most from my setup. I know that i'll be able to play sc2 in medium settings (or may be high) with 6950, because i just feel more comfortable over 150fps. ( Now i'm playing at low with 4770 crossfire), and also i know that this is an issue about sc2, i don't expect too much.
So, until i buy a new mobo and cpu, i'll be fine with 6950 i guess. I just wanted to be sure about bottleneck issue.