To me the only thing that matters to this argument is that Talbot is signed only until the end of the 2015-2016 season, while the Rangers' starting, elite goaltender is in the beginning of a 7-year contract.
Talbot has shown enough to want (and deserve) a starting role somewhere. It can't be the Rangers, and shouldn't be the Rangers. So both to maximize his value as an asset and his opportunity elsewhere I suggest he be traded this offseason (assuming a buyer can be found willing to give up an asset of good value to the Rangers) and a vet backup signed to handle the light load as Lunqvist's backup.
Talbot hasn't played enough to show consistency. Who knows what he'll end up being. The Rangers right now have had the best, most consistent goaltender in the world since he entered the league. There's no room to promote Talbot, sadly for him.
But having an excellent backup who is ready to start is a good problem to have. If by some stroke of luck Talbot indicates to management that he's willing to stay as a backup for another year or two, by all means sign him again, but in any other scenario it's time to trade him. And that trade is well deserved.
Talbot has been a good soldier and a well-loved teammate. He deserves a shot to show what he can do as a team's starter.