First, thanks for the congrats. The concern I have when a team gears its defense to stop one person (especially a QB like Newton) is that you now are defending with 10 players. And that usually doesn't work. It's a matter of the linebackers being very aware of what's going on. Oregon has more speed on defense that Auburn has seen all year. Routinely other teams have 10 yard gains reduced to 5... In addition, they are a small defense so they will have to tackle his legs or he will shed them. We also have to tighten up our pass defense and narrow his passing lanes. He's a good, but not great passer. I would make Auburn a slight favorite.
Nick Foles isn't a slouch, neither is Jeff Teul, nor is Stephen Threet. The Ducks have played some great QBs this year. None as diverse in game than Newton, but I like our chances because I don't think Auburn has a very complicated offense.
If anything, our defense should be completely comfortable playing against the spread. Hell, those guys play against James, Barner, and Thomas in practice all the time. Someone like Newton shouldn't be anything special I'm mostly worried about our smaller guys trying to tackle Newton's big frame.