The way I see it, there are 4 elite teams in the AFC. The Patriots, Colts, Jaguars and Chargers are all pretty much guaranteed playoff spots with each capturing a division title with the exception of either the Colts or Jags. So with that, there are two playoff spots available for the AFC North winner and the final wildcard spot.
Let's assume the Browns win the North and edge out the Steelers.
This means the Bills have to beat out Pittsburgh, Cincinnati, Houston, Denver; whoever might be a bubble team in the AFC. All of these teams are middle of the road and it just comes down to gets better bounces.
The Bills do play a pretty easy schedule so it's very possible. If Buffalo gets that 6th seed, I won't be surprised, but I'm not ready to predict that just yet.