Peyton Manning and the Indianapolis Colts were in the Super Bowl just two short years ago, ball in the quarterback’s hands, three minutes to go. Manning threw a pass intended for teammate Reggie Wayne that ended up in the hands of New Orleans Saints defensive back Tracy Porter, and that, in retrospect, was the end of the Indianapolis empire. Last season, the Colts went 2-14. On Wednesday, they will release Manning. Where the Colts go from here is an obvious mystery, with or without the No. 1 pick in next month’s annual draft. Here in New England, the empire continues under the reign of Bill Belichick and Tom Brady, though we are reminded of an inevitable truth in the modern NFL: the landscape changes quickly.