And is it totally out of the question that Punk could gradually turn face again? WWE loves the surprise turn, the swerve, so while I'm not necessarily saying it will happen, it absolutely could. The fans love to cheer for Punk, so safe to say at some point, he's going to undergo a face transition.
Plus, there's plenty of heels around these days. With the continued emergence of the Shield, there are at least three heels right there, possibly more. Lesnar will definitely be a heel. There's speculation of another Jericho heel turn (an idea I hate). And who knows, there could even be another heel as a result of the main event of WM29.
Heyman cost Punk the title. Inadvertently. I don't have too much difficulty believing that Punk will be pissed off with Heyman because of it, especially as Heyman's attention starts to revert back to Lesnar. Would feed nicely into an eventual Punk/Lesnar program, for which a face turn for Punk would have to happen.