The three superstars I believe should break into the main event within the next six months are John Morrison, MVP and Mr Kennedy.
These three have the potential to be champions.
John Morrison - Currently my favorite wrestler in the WWE, Morrison is the most exciting person to watch. All his matches since the draft have been awesome and he appeals to pretty much everyone. Plus the starship pain is awesome.
MVP - If the WWE continues to push him, he can add a new spark to the main event on Raw. If he was having matches against Orton, Batista and Cena (and possibly Triple H) it would be something new. Personally, I wish they would turn Cena heel and have a feud with those two, but I doubt that will happen.
Mr Kennedy - Despite only just returning, he could be pushed right away, and I hope he is. As long as he stays injury-free, he could be a brilliant draw for fans on Raw. He gets people excited and has better mic skills than almost anyone in the company.
Morrison and MVP have been the best superstars to watch since the draft and I hope they are both competing for the title on their respective brands soon. With Mr Kennedy now back in the fold, having him and MVP on Raw could make it a lot more interesting.