Should they have the opportunity to draft Andrew Luck, Indy may part ways with Manning. Considering his age and recent injury history, the Colts may not get much back on the trade market.
So if they release him, will the Jets, who are not happy with Mark Sanchez, sign him?
I think San Fran, Dallas, the Jets, and the Ravens are all teams that if they don't get to the superbowl, they will feel they underachieved. Excluding San Fran, all of these teams have decent QB's but the blame for losing in the playoffs will fall on the shoulders of the QB. Any one of these teams would be an instant superbowl favorite if they aquired Manning. I think that teams like this would jump all over the opportunity to sign Manning should he become a free agent.
Sanchez and Flacco are not Super Bowl caliber QBs. I guess it comes down to how you define decent, but the difference between the Jets or Ravens (as currently constructed) and bona fide elite would be a QB like Peyton Manning. Either team's GM would give his left nut if they had a chance to acquire a healthy Manning.