There's alot of threads suggesting the current program with Cena and Kane leading to Cena's heel turn etc. but what if it's something different alltogether? No matter what your opinion on Cena,you have to agree that his superCena gimmick has gotten super stale,so something's got to give,whether it's a heel turn or not. However, maybe this is a chance to make Cena edgier, aggressive and maybe give him a new gimmick, even if temporary.
How great would it be if Cena put on a mask and went berserk,apeshit crazy on the roster or even facepaint, like a new age ultimate warrior? Kinda like how WCW did with Sting in the mid 90s when the surfer gimmick got stale. They had him betrayed by the horsemen and Hogan when he turned to the NWO,he came back under his crow gimmick which has been a consistent fan favorite for over 2 decades. Sting was and is considered the ultimate WCW company guy and the face of the company,much like Cena is to the WWE now and his gimmick of being the outlandish flashy surfer guy got old in the 90s. I'm not saying do the same thing, a Crow-Cena would look ridiculous,but this would be a great time to give him an edge with a mask or a facepainted gimmick.
I doubt it'd be a permanent change since I would expect Cena to remain Cena for the mania match with the Rock, but using Kane as a catalyst for a brand new character for Cena would definitely breath some new air into his gimmick,and IF it's a huge success,he can carry it over to the match with the Rock,and,no longer being booed out of the building,can capture a credible win over him.