I think that Cincy, Indy, and New England would have to disagree. As far as who won't be on your list from the AFC, I'd say that Houston would be the most likely to fall off, but seriously I don't see any of the teams that I listed falling out of the playoffs.
As far as the NFC goes, I'd say that the first two are correct and I think that Dallas will be in the playoffs as well, but I'm lost on the rest of the conference.