VT Dolphan
Pro Bowler
I'd let it slip and say maybe three. But I am under the impression all of the top guys expected to be great, won't be. Lynch, Peterson, or Bush will be a bust. One of them will achieve nothing in the NFL.
Running back is kind of a different position because I'd say that about 90% of their success is because of the offensive line. I really don't think there is much of a difference between most pro-bowl running backs and your "average" running back (with the exception of LT, he is just a beast). Look at Priest Holmes, he wasn't anything special in Baltimore, comes to Kansas City with Willie Roaf, Brian Waters and co. and took the league by storm a few years back. The opposite happened to Edgerrin James last year. If there are no holes to run through, its hard to pick up yards.
So yeah, I wouldn't be surprised if one of those top three backs is considered a bust at first, but if they get a shot on a team with a good o-line then they suddenly won't be busts anymore. Thomas Jones was a bust in Arizona, came to Chicago and has put a few thousand plus yard seasons. So its kind of hard to judge running backs IMO.