I did some scenarios on the ESPN playoff machine.
To Slim's point about the Saints needing to beat the Chiefs, for those holding out hope for the #1 seed, the only way we get the #1 seed with the Chiefs, Steelers and Bills being 13-3 is for the Chiefs to lose against the Saints and Chargers. If they lose against the Falcons (doubtful) and Chargers and all three of us are tied at 13-3, the Chiefs are still the #1 seed.
With all that said, go Saints! And of course, go, go Buffalo!!!