I'm not sure that the key will actually be pass rush (although it is significantly important). Brees spends half the game throwing to his receivers, even when they are well covered. If our defensive secondary is able to trust each other (especially the safeties), the CB's can cheat on a few routes and end the Saints' hopes early.
It would be incredible to see our defensive backs put together a full game that looked like the second half of ther SD game.
Oh, and Peyton F-ing Manning...