I think I'll list a few obvious ones first. (not including world title pushed young stars like Sheamus or Swagger)
1. Albert del Rio: The Next Rey Mysterio in terms of microphone skills and entertainment, the only major difference is that Alberto is much better in the ring than Rey is, and is more capable of working with guys of difference sizes. Sure, Rey can pull off matches with big guys but it's always going to be the same thing. The underdog angle,which gets on my nerves after a while. How many times can Rey really be considered an underdog? On top of that, he has several wins over Big Show and Kane already, so it's not as if we don't we know that he can beat them already. With Alberto, we don't get the same angle each time. It can be a legit contest between Alberto and any other opponent where we aren't reintroduced to the same old underdog story each time.
2. The Miz: Do I need to further explain? He's just The Miz who after four or five years in the WWE is reigning WWE champion and gaining massive heat as such. A few years ago I would've been saddened by a Miz reign because from 2006-2008 he was your average trash wrestler who could get by on looks and charisma, but since 2008, Mix has done nothing but improve rapidly. I think he has the look and talent to back up him getting the strap. Long live the awesome one!
3. Dolph Ziggler: Even from the Spirit Squad days, Nicky, aka Dolph Ziggler has had some talent. The issue back then was the male cheerleader gimmick. But now Ziggler has been repackaged into this great looking and gifted young star who can put on a great bout with anyone. His few matches against Bryan from earlier this year were phenomenal and he has managed to have great matches with the likes of Mysterio and Kingston as well. Take that charisma and wrestling ability and slap on a good female manager to keep him interesting and you've got a winning formula. We'll probably see Dolph with a world title within the next three years at the most.
4. Wade Barrett: Barrett was in the main event of more PPVs this year than Edge, Cena, or Undertaker, plus many more, and this was only his rookie year. I think that his recent booting from the Nexus will only lead to better things. A big feud with CM Punk, leading on to reignited feuds with Cena and Orton will all make for a winning formula for Barrett. I don't see any need for further elaboration on Barrett.
Those being stated, here are a few that will also have some success but will either not have staying potential or will just have mild pushes before staying at upper mid-card (sort of like Sheamus right now, or Michaels late in his career).
Daniel Bryan, John Morrison, Kofi Kingston, Cody Rhodes, and Evan Bourne.
And here are a few that I'm not sure will ever make it past mid-card.
Drew McIntyre, Ezekiel Jackson, Zack Ryder, and R Truth.
Now a few of these people I would like to see succeed (like Ryder, Jackson, Bourne, and Bryan), however I just get the feeling they won't for different reasons.