Honestly this would be a good time to do a injury angle with Cena whether it be Punk taking him out and Punk faces someone else (though I want to see Punk/Cena hitc) or run a whodunit angle taking Cena out but Cena still makes the PPV but gets cost the match by whoever attacked him giving him a new feud.
I think if WWE was serious about pushing Ziggler, and the current route he's going, I'd be putting Ziggler in that position.