Would rather have Cena get screwed over by Miz like Rock did to Foley in their I Quit match. Because Cena isn't going to say I Quit, it doesn't fit his character. Heels quit, not the "never back down" "come get some" "never give up" good guys.
That is what I am thinking too, it would make it interesting and you can easily just make it where Cena loses, but then people will just whine about how Cena lost the belt and then re-won it. So for me much rather see him just hold the belt and see where they go. No matter what I think the Miz will still be in the world title scene, because WWE wants to keep him as a top star.