You know, at the end of the day this doesn't have to be CM Punk, a man who is sXe vs John Cena, a man who lifts shit. Nor does this have to be good versus evil. CM Punk and John Cena BOTH have underlying characteristics that could fuel a long-term program based exactly on who they are and the social commentary that it could produce, with both sides being controversial and carrying merit at the same time.
John Cena, at the end of the day, listens to rap music.
CM Punk, at the end of the day, listens to punk/hardcore/heavy metal music.
How does this work? Easily -- with Punk currently heel carrying around the militant aspects of sXe lifestyle, he can carry the militant attitude over from straight edge and onto the social perception that comes with rap music, or atleast the social perception that a heel would have towards it.
Punk could come out and preach to the world his beliefs that Rap music encourages gang activity, it encourages a butchering of the english language, it encourages objectification of women (which is one thing that if you've ever read Punk's livejournal from his Indy days -- doesn't like) as well as drug use and alcohol consumption 40 ounces at a time. This allows Punk to not only act on his straight edge philosophies, but also his hatred towards hip hop society as a member of the punk rock movement that was incredibly anti establishment in its roots.
This could lead to Punk mentioning how many rappers have been gunned down in the past couple decades, the east coast / west coast wars, tupac/biggy, so on and so forth and how the fact that John Cena endorses said music and how any parent with a functioning brain would keep their kids as far away from that as possible. Perhaps, encouraging their children towards the "Choice of a New Generation".
How does Cena react? The same way he always does -- he admits his few flaws, but justifies them by encouraging children and their parents to monitor what they're listening to, and to make you choices wisely. Cena would chastise Punk for being so closed minded and hypocritical due to the fact that Punk listens to music that often encourages civil insurrection and anarchy (it doesn't, but the majority of wwe fans wouldn't know that. they could make some shit up for that). Thus resulting in a confrontation.
This fued could really tell a couple of stories. The first story being that we live in a world of shades of gray. John Cena, the protaganist - living a world inside of his own flaws, being a saint who's also a sinner, and CM Punk, the antagonist -- a man who preaches the world in black and white, only to be outed in gray lines himself.
The second story could also be that of a social commentary -- which many believe CM Punk is/was born to do. Matt Stryker as a color commentator in this fued would be immense in the sense that as the matches go on, Stryker would as usual -- begin conducting a seminar in the backdrop of each man's philosophies and lifestyles. The promos could really push the envelopes of the PG rating and shine lights on Hip Hop and Hardcore at the same time.
Just my idea.