I think HHH is going to be the catalyst this year. HHH has been on the level of the other legend faces the past few years. He comes back for a match, gets the nostalgia pop and then goes back to his suit. It works, but honestly they have more and more of those guys like The Rock, Brock, and Taker among others. What they're missing is a true top heel, which is the character HHH is best suited to play.
I think the motivation would be the night where everyone walked out on him on Raw. Even JR didn't stand for him. He had one of his best friends turn on him, the entire roster turned on him, and hell even a large portion of the crowd did as well.
With his actual position of power in the company combined with his history as top heel and ability to work; he could take the "evil boss" concept to a whole different level. He's not too old to work a nearly full-time schedule (tv and ppv mainly, maybe the bigger house shows) and if everyone is honest with themselves; the second HHH would turn heel, he becomes the best heel they have on the roster without any shadow of a doubt.
The DX reunion of 2002 was what launched HHH into arguably the best 3 year period of any heel in the last decade. I could see the DX reunion of 2012 could be the beginning of his next heel run.
His turn would/could drive almost every major storyline until Mania. Have him use his real life proclivity for nepotism in storylines. The guys he likes are pushed, the others are not. Have him use the proverbial "glass ceiling" to just decimate the roster. If done right, the regular jack offs and the IWC would both hate him because he could be anti-Cena and anti-IWC favorites and it would make sense.