For guys on TV now, the jump up to the main event is extremely difficult. I can't think of a single babyface midcarder the crowd is clamoring for to get a shot at the main event. Ten years ago, we had Edge, Chris Benoit, Eddie Guerrero, Chris Jericho, and others who had the crowd behind them, who were ready to get pushed up. I think WWE's failure to build a good mid-card is a serious problem. Guys like Zack Ryder, Santino Marella and Kofi Kingston wouldn't be taken seriously as they are. For stalled-out midcard acts, there's really only one way to move them up, and that's a significant character shift. That's how Rock and Stone Cold were built into main eventers (yes, they were built, they didn't do the whole thing themselves). Do you think any of the 3 guys I mentioned above could pull off a heel turn and/or a run as a serious wrestler? Oddly enough, I think Santino's the best bet. He's been such a cheeseball and he's done so well to get the crowd on his side solely as a novelty act that I could see him going the JBL route. Once the crowd takes some (any) of these midcarders seriously, maybe then they can move up to the top of the card.
Your other best bet is taking a new guy and pushing him to the moon. But they can't sem to do that without making the pushed wrestler into a cheeseball (Brodus Clay) or a Goldberg retread (Ryback). Let's try something novel, WWE. Take a good-looking guy who can talk a little, give him an interesting (but not weird or novelty) gimmick, let him beat some midcarders, and see where it goes from there. Oh wait, that's exactly what WWE did with John Cena. Well, do it again then.