I would like to see us take Gholston or trade back and get Harvey...Not sure if Colvin will be back, but even if he is, you let Gholston learn from Colvin and Vrabel...Putting AD inside will enable Seau and Bruschi to split reps again, and further, give some learning time for whoever else joins the LB corps whether that be the draft or free agency.
If the Ohio St cornerback declared, then I could see taking him, but based on the number of people who have declared, I'd say the best option is clearly the pass rusher. These guys wreck games. Get as many pass rushers as possible IMO. We already have a very good run stopping defensive line.