Being better than one of the historically best defenses ever will be very difficult.
We will be getting everyone's best every Sunday being the reigning super bowl champs. However, this wasn't much different from this year.
Also Pete and company will have to fight the complacency problems and keep the guys hungry.
All told, I don't think it'll be as good as this year but it will be close. I still see a #1 pass defense and a top 3 scoring defense next year.