I've read that he wants to be more of a tweener and that his favorite gimmick was his thuganomics gimmick. He mentioned that bit about his thuganomics gimmick during an interview in Philly last year too.
He has also come out and said that he enjoys his current gimmick which I believe is because he is a company man and will do what he is asked without causing drama.He understands that he is a role model, he genuinely enjoys being a role model for kids, and knows the WWE needs him as the top face.
If someone else came along to take the mantle as wwe's top face or could at least be a viable alternative (or the fans stop buying his merchandise), I don't think cena would mind going heel. He would probably enjoy it.
Problem is that super cena has become so big with children, especially make a wish kids, its almost impossible to see him going heel any time soon.
Originally Posted by Sam Hinkie
"I'm probably pretty boring to watch a game with because I''m all about expected values. I don''t even care if it goes in or not, I'm all about, '‘Should it go in?'' I can live with randomness. I mean, if it''s a close game in the end, yeah, I''m just like anyone else. But I just want us to play the odds all the time."
What a lot of people forget is that the five moves of doom are the prelude to someone's finisher. That is it nothing more. Most famous was Brett Hart's. Brett never strayed win, lose or draw you could count of those moves towards the finish of the match whether he hit the finisher or not.