The way I see it, if we don't count people that are already in the main event (like Edge, Orton, Cena, etc), this is how things are going to turn out in the next few years...
MAIN EVENT
1. John Morrison - Incredibly impressive in the ring, still a little shady on the mic but he's hilarious, and the guy is improving in every aspect at an exponential rate. He's the next Shawn Michaels in my opinion.
2. MVP - Really, the only thing holding MVP down right now is that he needs to add a few more moves to his repertoire, particularly a better finisher. He's got the charisma, he's solid in the ring, and he's over.
3. Mr. Kennedy - His biggest fault is bad luck, in my opinion, but he too needs a solid finisher that fans can enjoy watching. He still needs a bit more time in the ring to work out the kinks, but if he continues an upward climb, he'll be great in a while.
MIDCARD
1. Cody Rhodes - He's still a bit green, but he's not too bad in the ring and on the mic. By next year, I think he might be a good contender for the IC title, and in enough time, a really, really good champion. We'll have to see, but he's got a lot of potential.
2. Paul Burchill - Despite how horrible he's been booked lately, having his sister need to help him to get wins over jobbers, Burchill looks like the type of guy that could be a good heel midcarder.
3. Ryder & Hawkins - Way too early to tell for these guys, but Ryder especially has me wondering if he's going to break out in 2 years or so and make a good name for himself.
4. Kenny Dykstra - Dykstra is already pretty good and he's only, what, 21 or so?
5. Kofi Kingston - I think Kofi's act is going to wear out eventually, and he won't have a jet-fast ride to the top, but if he works on learning some more moves, maybe telling a story in his matches as opposed to just flipping around really fast, then he has the potential to start rising up. Maybe he'll be the next Booker T.
6. The Miz - A year ago, I absolutely hated the Miz. I thought he was an abysmal wrestler that should be fired and a total joke. But you know what, this guy has been improving VERY quickly. I would actually consider him an IC/US title chaser already. If he continues improving, who knows where this kid can go?
UNKNOWN
1. Shelton Benjamin - Its a shame you can't merge him with the confidence of Burke, cause you'd have one hell of a superstar right there. Shelton severely needs to work on his mic skills and most importantly, developing an original personality for himself. He has all the in-ring talent to go far, but he isn't over enough to be pushed.
2. Elijah Burke - With MVP beating him out in certain categories as well as Shelton beating him out with athleticism, I don't think there's a true place for Burke to make a name for himself. He could be a good IC/US contender right now, but I can't see him breaking out and becoming huge.
3. CM Punk - Unless Punk stops being so incredibly predictable in his matches, I can't see him booming. He'll probably get a world title run or two in the future, but if things stay the way they are right now, he'll be fading into oblivion soon. He isn't nearly as popular as he was before, it seems, and there's no life being pumped into him. Personally, I don't think he's ready for the Money in the Bank. I think a good midcard title run would do wonders for Punk, but the WWE seems to think otherwise (unless he's just holding the case for when Hardy returns, as that hasn't happened yet). We'll have to see if Punk adapts or flattens out.