So...
It seems to me that the groundwork is being laid - intentionally or otherwise - for a Cena-Bryan feud, with Bryan as the quasi-heel (although he'd undoubtedly have a lot of fan support). The motivation for Bryan is just about perfect: why does Cena get a free pass from The Authority - thrown into a title match before he's set foot in the ring following injury - but Bryan keeps getting screwed over at every turn because he's not "Good for Business?" Never mind the fact that he beat Cena clean as a sheet in the middle of the ring. Cena, meanwhile, has a perfect defense: he chose to defend the title against Bryan at Summerslam, and when you go all the way back to it, he's the one who brought Bryan back into the company after the Nexus kicked him aside (or if you want to go for extra realism, after he got fired). It could even work with both of them winning their matches on Sunday to make it a title unification feud, although I doubt they'd go there since multiple belts means multiple toy belts to sell to kids (which, of course, is Good For Business).
So, you think they'd go in this direction? Or do you think they wouldn't want to cut off sales of "Yes! Yes! Yes!" shirts by making Bryan a quasi-heel?
Oh, and by the way, the NY Islanders' "Loudville" fans (college kids who get access to cheap seats an hour before the game) have started doing the "Yes!" chant after the Islanders score. You think they'll have the good sense to do something with that when Raw's at the Coliseum next month?
I think you're overlooking the most obvious and lame and thus most likely reasoning behind a Bryan-Cena title feud: The Bellas. It's a Bella in every corner!