I was using the New York Times playoff simulator to see how the Bills could get in with a 9-7 record. It is actually very feasible.
I have the Bills winning @ Chargers, home to Colts, home to Dolphins and @ Dolphins. That gives the Bills a 9-7 record, 3-3 division record and 7-5 conference record.
When I put the outcomes of the other games, I didn't put anything unreasonable. For example, I have Baltimore beating the Browns, Colts, Cincy and one other team to get to 8-8. I have Miami losing to the Pats twice and I think they end up 7-9 or 8-8. I have Jacksonville winning the South and Tennessee getting the 5th seed.
So Baltimore gets to 8 losses, Miami 8 losses, the Jets get to 8 losses, and then the only other team I would consider would be Oakland, and we have the tiebreaker on them, not to mention they play the Pats, Chiefs, Chargers. I think 9 wins will get us in in many cases.