Here is the way I see it with their #1 pick. Detroit should only look at our Houston Texans and the two times we picked #1 overall. When we got the QB, he didn't pan out because he came into an already bad situation, no offensive line. When we picked the DE, The Great Super Mario, we ended up getting a Pro Bowler, and in two seasons our team has gone from beatable to respectable. If they go QB, you gotta give him time to adjust to the speed of the NFL and learn the offense and blah blah.
I'm not saying go DE but I am saying to handle the trenches and get better from the inside out, even if that means going offensive line.
Think about the QB situation. They already have Culpepper and though he hasn't been his former self, he is alot better than what you are going to possibly get in a rookie. I would even say, use the other pick on DL.
The Detroit Lions are possibly going to be picking in the top 5-10 next year. The QB draft class next year is going to be way better than that of this year. Mccoy, the kid from Oklahoma (name escapes me right now), Daniels from Missouri just to name a few right off the bat.
That's what I would do with my set of first rounders.