I think it's gonna be Luke Cage. He wasn't mentioned in Wizard's "Who Will Be Cap?" article, and he is a fave of golden boy Bendis. Luke has no codename and already has super powers "on par" with Cap's, Plus he's bulletproof, so he wouldn't need the shield.
I just think of any hero in the Marvel U, the hero right now that embodies modern America, would be Luke Cage. Think about it. He's a young father who looks out for his neighborhood who'd been given a second chance at life after a jail sentence. He's tough, smart and is a high level street fighter. He'll have the chance to prove his leadership since becoming leader of the New Avengers.
I may be wrong, but if I was in charge, I'd happily make Luke the new Cap. He fits the mold, imo.