From my understanding, Cena got the belt because WWE prefer to give the fans the happiest possible outcome at WM ie the top face wins the title in the ME. Hence why if a heel is going to retain they usually have that match half way through the night and if it's a face winning then they have them in the ME ie WM 24 Orton/HHH/Cena was 3rd from last because Orton won, and Taker/Edge was last because Taker won. This year, for some bizarre reason, they opted to have the World title matches in succession at the end of the show instead of separating them with Taker/HBK like they should have, and both the faces won.
I didn't honestly think Cena was going to win at WM because i'd heard all the rumours about him needing time off because he's getting married etc etc so now i'm moving towards the idea that he'll either lose at Backlash or shortly afterward. I'm not saying Edge is going to beat him, i'm following the theory that they'll repeat what happened last year and have Punk come along and reclaim a World title for his brand from a bloody, weary champion, whoever that may be.
I'm waiting to see the supplemental draft and how SD looks after today. They've literally got Edge, Jericho, Taker, Rey and Jeff Hardy as their top talent on that brand now. WTF? That's terrible overall. So i'm guessing they'll have Punk win the belt and fill up the 'ME' tier on SD, and this Kane fued we all read about being advertised will probably happen now that they're both on SD (either that or another Taker/Kane fued -yeesh!). But seriously, SD needs an injection from ECW. I read that Morrison is now on SD, hopefully Christian came up as well. I for one was super annoyed monday night when he didn't get drafted (glad he won the draft pick match for ECW though)
Anyway, as i was saying, i think that Punk will indeed cash in MITB and reclaim the WHC for SD. His first fued will be with Edge, then his next fued will probably be Kane, then Jericho and then, dare i suggest it, the Undertaker, and then we'll have 6 months of triple threat matches and then it'll be WM26!!!!