A lot of really good points here and excellent dialogue. Here's my take:
I truly believe Dante is going to be THE DUDE next year. He has sat back and learned a ton over the last two years. At UCLA he gained valuable game experience that showed him he has the tools, but also that there is still much to learn. This year he took a year to be a true student of the game. He shadowed DG as closely as he possibly could and learned what it takes to be a true professional.
One factor that hasn't been highlighted enough is the intensity of Oregon's practices. Every player who's been under DL’s coaching has mentioned how tough the Monday, Tuesday, and Wednesday practices are, and how they make Saturdays feel like a breeze. Dante has been going head-to-head in practice with one of the top defenses in the country day in and day out. That alone is invaluable experience.
A few people have mentioned you can't risk having an unexperienced QB in there with the chance of losing a game, but that is the furthest from the truth. Who cares if the Ducks drop a game or potentially even two games during the season? This is no longer a time where a single loss will derail your season. It is ok to drop a game as long as you learn from it. With the current playoff format the Ducks would be in their 3rd consecutive year making the playoffs, even with those losses.