They are still pretty hopeful in my mind.
Only two playoff spots are available for the Bills - East division winner (ideally) or 2nd wild card team (realistically). Here is why.
Lets quickly breakdown each division (being simplistic but realistic)
The AFC North plays the NFC West (weakest division in football) and AFC South (second weakest with the absence of Manning). Throw in a struggling Cleveland and a floundering Cinci; Pittsburg and Baltimore are going to rack up wins (I think 12 each) - #5 playoff spot will be gone.
The AFC South plays the AFC North and the NFC South (very strong this year). Houston will probably win the division.
The AFC West plays the AFC East (toughest division in football) and NFC North (second toughest division) [North over South - look at wk 1]. SD wins the division this year.
Contenders against Buffalo for the last wild card spot:
New York, Cleveland, Tennessee, Oakland
I think Oakland is a very good team (will beat NY this week) but plays such a tough schedule (GB, Chi, Det, Minn, NE, Buff) and lacks the elite Qb.
Tennessee could do well but must play NO, Atl, TB, Pit, and Balt along with Houston twice and don't forget Buffalo!
Cleveland has the most favorable schedule but probably will stumble along the way (see wk 1)
New York presents the toughest challenge to Buffalo but they play head to head twice. These will probably be the most important games for Buffalo all year (in terms of making the playoffs). I expect a letdown from NY this year and they have looked very beatable so far. This is what made Dallas' meltdown such a bummer.
Interesting things happen in the NFL but this is probably a two horse race between Buffalo and New York. Watch and see!