There's going to be a few bidders for that #1 pick. If they're intent on keeping Manning, then they'll be looking to deal that #1 for a package of picks and maybe even a defensive player. That defense has been exposed this year more than anything. Manning is going to want some fresh talent, including another receiver. They could be very interested in Blackmon or, depending on how far they trade back, Richardson at RB.
Basically I think the Colts had an epiphany with Manning's injury. This team is built around 1 player and when that player gets hurt then they're screwed. They're going to change that, I think. That means upgrading the O talent around Manning AND building a more conventional defense.
But if they're OK with getting rid of Manning, then all bets are off. Who knows.