Over rated, yes, from a purely quarterbacking standpoint he is one of the worst in the league. However, he has other skills that get the job done and get Ws (which, to me, is all that really matters).
His WRs aren't very good, but I still don't think he would be a good QB even if he had Chad Johnson, Randy Moss and Marvin Harrison, he simply isn't a very good passer and likely never will be. Doesn't mean he won't be a winning QB.
Interestingly we are at the same point with Young as we were with Vick in his 2nd or 3rd year, their stats stink but they are winning games. Everyone kept going on and on about how Vick was a "winner" and his stats didn't really matter, which is what they are now doing with Young. Ultimately Vick didn't improve at all as a QB and both his growth and team's success were stunted b/c of it. I think Young will be a decent winning QB, but never a good QB. Unless his passing skills improve and improve greatly I think his team's success will also be limited to making the playoffs, winning a game here and there but ultimately getting bounced in rounds 1 or 2. You just can go deep in the playoffs if you can't pass.