I never said that the Broncos should be discounted. I just think their moves have been overrated. It seems that the media and people around the country think the Broncos built a defense that will rival the Seahawks' (ok, a bit of an exaggeration, but not much).
I don't think the Broncos will be as good as last year just because it is doubtful their offense can be as good as it was last year. I expect them to have a top offense, but I don't expect it to be a historic offense.
Even if their defense gets significantly better, I don't think it will make up for the decline on offense. When they were scoring like they were last year, their defense was almost irrelevant in most games. If you can be up by three or four scores in the first half, you can afford to have an average defense and still win by three TDs.