I wont agree its a year of development only, and I doubt Parcells will either. He want's to win, and will only make the move if he believes Romo is ready to win. That's the point of 3-4 years of developing him in a backup role.
I will, however, agree that it may end up being a year of development whenever Romo gets the nod to start, I just wont concede that's all we can hope for. If he were a rookie I would think differently.
But the thing is, there ALWAYS comes a time when a young player replaces and old one, and Parcells has been around long enough to have done that a number of times. Parcells does covet experience, but there ALWAYS comes a time when you have to weigh the benefits of experience against the benefits of energy, enthusiasm and athleticism - obviously the maturity and knowledge levels of the youngster come into play as well.
But let's not act as if Parcells has never passed the torch from an aging player to a younger one - he knows there is a time for everything, and at some point that time will come for Bledsoe. I just personally believe that if Bledsoe and the offense struggles somewhat consistently that Parcells will make the move - it just seems to clear that he likes Romo's potential enough to make the move.