Cumberbatch was awesome as Khan. I just wish we got to see more of him! Hopefully STXIII will open with Khan being thawed for trial - and escaping.
The whole idea that Starfleet thawed Khan and tried blackmailing him into building weapons for a war with the Klingons... it's utterly insane. And awesome. It played the AU premise to it's fullest - you could not have told a Khan story any less like "Space Seed" or "Wrath of Khan" if you tried.