Wheeler may have been a stretch at five, but certainly not the extent people were saying on draft day. A lot of rational people said he'd have been a reach in the top 15, and some even said he wasn't a first rounder. Obviously he still has a lot to prove (having never played an NHL game), but as of now, as strong as that draft has looked early on, there are only a few players drafted after him I'd consider better, and I'll go even further to say he might even be better than Ladd or Barker.
Wheeler is still a junior in college. I wouldn't be surprised if he went back for his senior year and then spent another year in the AHL on top of that. He was drafted to be a project player, and the Coyotes will take their time with him. That being said, he has already shown to have every tool you would want from a big man, with one exception: consistency. Some nights he will look like Eric Lindros and others like Oleg Kvasha. He has wheels, hands, grit, everything; the problem is simply that he only appears to be able to put it together once in a while. If he can find any semblance of consistency, he will be an perennial all-star. More likely, though, his top end is similar to that of someone like Eric Daze (minus the injury woes): a big guy who doesn't hit as much as people want, but who can still put up a solid 70 or 80 points. He'll probably never be the stereotypical Lindros/Neely power forward, and because he's 6'5 and 230 lbs., people will want him to, but he can still be a great contributor.