I love Tillman's play and all, but honestly, if Revis is resigned, cornerback may be the position with the most depth on the entire team.
Doubt Bill will bring in a 33-year-old corner coming off an injury in when he's got Arrington, Dennard, Ryan and Butler in the foreground.
If there's one position though that seriously could use an upgrade, it's Strong Safety. I thought Chung did a solid job back there this year, but imagine a big Kam Chancellor-type to go along with Revis, Browner and McCourty? Ugh, that would be insane.