I've been thinking about this a lot lately. I want the Lions to trade back as far as possible tot he late 1st round and pick up as many 2nd and 3rd round picks as they can. I think this is a very deep draft going well into round 3.
Having said that, since in this scenario you don't want trade downs, if they are forced to pick at #9 assuming that the following players are taken: Bush, Ferguson, Young, Leinart, M. Williams and Davis. Obviously two more guys go here before the #9, but it's a BIG ? who.
I voted other. Assuming, all the other guys are available, I say the Lions should take DT Holoti Nagata! He has rare size at 6-4, 338 pounds and has great speed and quickness for his size. He will stuff the run and can make plays behind the line of scrimmage. You pair him with Pro-Bowler Shaun Rogers and you have the makings of the Tampa Bay defense 5 years ago when Sapp and McFarland were in the middle. The problems they would cause as they both would warrant double teams and there just aren't enough blockers, would create havoc for offensive lines. With Shaun Cody coming in on plays to rest them both and play a little DE on running downs would form a lethal defensive line. Wilkinson is likely going to retire, so this would fill that hole and even be an upgrade as he didn't play up to potential given his size.
In the second round, I would want the Lions to go after a speedy linebacker to play the MLB or WLB to take advantage of the space these guys would take up.