Anyone picking anything other than "Andrew Luck" or "Trade The Pick" needs their head examined.
Gotta take luck - you get yourself great qb for next decade.
Trade Manning and any other older vet who is worth a damn, and start from scratch.
Combine all of the answers above and there is your answer.
Even if Manning comes back what happens when he's gone in 2-3 years?
Whether they trade Peyton or keep him it doesn't matter they need to take Luck either way.
UNLESS.... Another team makes an offer of draft picks for Manning that is just too good to turn down.
There are other QBs in the draft other than Luck. 2-3 years is plenty of time to groom someone learning under Manning. If you remember, there was a guy drafted by the Packers quite a few years ago who sat and learned from a legend and is now one of the best in the game. The colts WILL draft a QB this year, there is no question about that. But it does not have to be Luck, especially if Manning returns...