As much as I would like to agree, I can't. We have been saying this for 3 or 4 years now. The beginning of the downfall will be when Manning's physical talent starts to errode, which unfortunately is likely to be around the same time as Brady's.
Exactly, the reason why these teams are the best is because of the QBs and the front offices/coaches, it's as simple as that. They will continue to be great too. And really, when you look at the Colts' roster, the best is yet to come because there are few guys that will be free agents over the next two years.