i should note before i say anything that i haven't seen any of the new developments from last night's raw besides cena's opening promo
i agree with lopen that the feud isn't really about the title
the title is on the line in the match, but it's really just a symbol of the wwe as a whole
most guys challenge for the title because they want to be champion
punk has no interest in being wwe champion (in kayfabe at least). all he wants is to have the belt in his possession when he walks out the door. he doesn't want to defend the title or represent the wwe as its champion, he just wants to wreak as much havoc on the wwe as he can on his way out the door. everybody knows how sore a subject the idea of somebody leaving with the title is for vince. he screwed his biggest star and most loyal soldier to prevent it from happening before. i'm really surprised they haven't brought bret back to be involved with the angle. it seemed like the perfect opportunity when they had HBK back to promote his show and even had him interact with punk.
edit: and the cena getting fired thing makes it even less about the title because now he's fighting to keep his job, which is a bigger deal than fighting to keep his belt. with cena defending wwe's honor and with his job on the line vs. what can potentially happen if punk wins, i can't really see cena losing.
edit 2: here's the stipulation of the match listed on wiki: Singles match for the WWE Championship. If Punk wins and leaves Chicago with the title, Cena will be fired immediately. the way that's worded makes it seem like cena can lose the match and not get fired, assuming the mitb winner cashes in and saves the day. based on his feud with punk, i'm assuming that person would be rey, especially since rey vs. cena (or rey vs. cena vs. punk) would be a huge summerslam main event.
--
http://img.imgcake.com/baronvontoast/1304312287012jpgen.jpg