Upgrade at any available position.
I think the key is balancing experience with youth at each position. Guys who can fill in when the current starter is gone. If MIA gets Brees, they MUST get a young QB (Brodie Croyle would be ideal for Brees to groom). If MIA gets T.O., they need to get a young kid (rookie, 2nd year) for him to groom. Kevin Mawae would need a young kid to groom. Get older guys who are hungry to win a championship and young guys dedicated to be part of a team instead of a showboat.
Although I'm psyched about the prospect of signing Brees, his injury is about as bad as it could have been (Throwing arm). Incentive laden contract would be ideal. Culpepper's injury is as bad as it could have been for him (Mobile QB's knee). Patrick Ramsey is healthy, he's been in the league a few years, and I'm sure he'd fit into the "hungry to win" category. If Spurrier didn't mess him over completely, I'd be a little less reluctant. Harrington was my pick for QB, but I think DET has decided to stick with him. It helps MIA's case for Brees, but Harrington's healthy and just as young. BEST case scenario would be to draft Croyle, start him, and have him play virutally mistake free (Orton-esque). He wouldn't have to win games his rookie year, just not lose them. The defense, Ronnie and Chambers would help with the winning.