On the NFL Network Archie said that he doubts Peyton will be a Bronco.
The NFL analysts said that Peyton will allow himself to get completely healed up and then test his ability to throw the ball before making a decision.
I would give the odds of Peyton NOT retiring as very low, but if he did come back that team would have to have a great surrounding cast... especially the OL and RBs. Defense would need to be very good too. He's not coming back without an outstanding possibility to get back to SB51.
The opportunity of going out on top will most likely trump every other factor. Unitas, Favre, Montana all put on sad displays that PM is totally aware of.