Firstly, I understand the problems people had with Sheamus having the world title. I have howeever never quite understood the issues surrounding ADR. He is simply fantastic and fully deserves his rise to the top of the mountain. He may be green in terms of years spent in the WWE, but you would never know it to look at the guy in the ring or on the mic.
Anyway, on to your main question. It's obviously hard to really think of too many guys who will get close to the main event position and not see the world title at some point. Obviously the industry has changed and the belt is moved around far more often than it has been in the past, leading to the likes of Jack Swagger having already had the title.
But, if I had to guess, and despite the fact that he has the near guaramtee of a chaampionship run with the MIB suitcase, I just can't see Daniel Bryan having the WWE or World Heavyweight title. So, I guess, if I had to go for someone, it would be him. Although I say that with the thorough expectation that he will get the belt at some point in the near future.