I don't think that Vince Young is ever going to be the number one pick in the draft. If he's a projected first rounder then he owes it to himself to give serious consideration to coming out.
Leinart on the other hand may have cost himself some money. I agree with Mili that he has probably dropped after this season. If I'm picking 1st then Reggie Bush is absolutely my guy. He is going to be the best player available in the draft and can be an immeidate game changer. You have to take a guy like that no matter what. After that, with my limited knowledge of who is coming out in this years draft, a team will probably go with need. Do the poor teams who are going to have the high draft picks need QBs? Does Cleveland need a QB? Frye is going to be the starter at some point this season, and if he lights it up would Cleveland draft Leinart? Houston? David Carr is still young. San Fran? Minny? Depending on the draft order Leinart could drop considerably.
I could be way off, though.