I would expect our priorities to be (in order): QB, DT, CB/S, WR, LB.
I don't think LT is a pressing need. Every team could use a franchise LT, but our OL is above average. Our CB/QB play is not.
Ngata would be a beast, better than Gardner. Traylor won't last much longer, and I don't think you can count on BOTH Vickerson and Wright. Hopefully one pans out. With Ngata, that's a monster/athletic inside line.
I'd be tempted, if we get a top 5 pick, to trade down with someone in the Bush/Leinart/Hawk race and pick up Ngata and a QB... It is illogical to think Leinart is in our reach. He's a top 2 pick. But there are more QBs to be had here. I am not the biggest Vince Young fan, but he would be exciting to watch. I'd rather go 8-8 and miss the playoffs with an electrifying QB than go 10-6 and miss the playoffs with Gus Frerotte or some other stopgap. I think Vince Young is improving week-to-week and has high upside.
The other thing in our favor is Meuller. He has eyes for QBs.
Getting out of this draft with Young and Ngata would be a smashing success, in my opinion.