As probably the biggest Broncos fan on the board, I'll say that they're good enough to contend for the division title (especially given the 2-game headstart, which they're incredibly fortunate to have), but not good enough to make any serious noise in the playoffs. As good as the offence has been, the defence really hasn't gotten any better than it was last year -- San Diego and New Orleans, both with very good offences, tore off huge chunks of yardage, especially as the games wore on.
I will say that Jay Cutler, although he's still a bit prone to making mistakes at crucial points, seems to have taken a quantum leap forward from last year. He's finally showing the skills we were promised when he was drafted.
Now, the AFC seems a lot more wide open this year than in previous years, so they might become a legit Super Bowl contender as the season goes on, but that would be a (pleasant) surprise.