That could be possible. The theory behind the Dragon Shout to summon a dragon is that you know his true name in draconic, and being the Dovahkiin you have the power to force him to aid you against his will. I'm thinking that one will be part of the main quest. But who knows :shrug:
What I mean is, yeah, it could be like the part of the main quest in oblivion (exact name I cannot remember) where you must get martin a daedric artifact.
He does not specify which one, and you must go on a quest for a said daedric prince.
I would like it to be similar to that, but for the quest to get a dragon to be quite lengthy.