I think that's a very fair question to ponder, but I don't want to get into the mindset of "no one can compete with us," either. After all, it's way too early to play too many of these scenarios out for reasons you mention such as the suddenly rapistless team from Pittsburgh. Different scenarios will play out over the next few months, of course.
I'd have to guess that Indy turns things around enough to win their division and host a playoff game, so they'll likely end up right around where they were last year in terms of having the ability to pull off an upset and advance. The only real difference is that they didn't move forward and prove themselves to be the new darling of the NFL, at least through week #3 anyway.
There's always the possibility that Cincy has actually improved, and that their past postseason failures don't apply for the future, but none of us are going to believe that until we see a larger sample size. Either way, they can be a pain in the ass.
As I mentioned, Denver and Manning are probably going to be in the top few AFC teams, and there's always the possibility of seeing a wildcard contender like the NYJ of 2010. If that's the case, I suppose we'd probably put teams like Pittsburgh, Buffalo, and maybe KC in that grouping. Baltimore may get back on a better track and end up something closer to their usual 9-7 record, but it's not looking too good for them at the moment. The Jets could continue to compete and end up around 9-7 just as well, I suppose.
I think you make a great point though, in terms of the Pats being in a pretty good situation, at least as it pertains currently.