Semi-related, I think I'm over the idea that there's ever such a thing as an "underdog" in the Super Bowl. Obviously there are extreme examples, and 07 was an upset on paper, but take two teams that have each played 18 or 19 games (plus pre-season), are battle tested through multiple playoff games, have two weeks to prepare, during which there are an untold number of distractions, events, and emotions, then mix that all together with the one-and-done nature of playoff football, and the matchup specific nature of football itself?
The Super Bowl is like a giant parity blender that chews up teams on paper and grinds them into an unpredictable pudding of awesome chaos. Not really comparable to a divisional round game.