I don't think Sean Smith is worth re-signing, especially if he is wanting $7 million a season. I think Smith has gotten a little better, but we need d-backs who can make picks and force turnovers. Some guys just seem to be ball hawks, like Ed Reed, and then you have other guys like Smith who can't catch a cold.
Anyways, I think a guy like Darius Slay, of Mississippi State would be a nice fit. I like his size....I think he is around 6'1" 200 pounds, and he knows how to make INT's and can really run with the ball. There are some nice vids of him out there....check out this INT against Georgia where he goes up in traffic to snag the ball and then runs down the sideline. He has great speed.