Beane and McDermott will need to nail the QB pick, especially if they trade up. If they trade up and miss (which will be apparent in a couple of seasons) they are probably finished since there will be a lot of losing; with multiple picks given up in lieu of filling in a lot of holes. I'm sure there is a guy they're targeting, and if the opportunity is there they'll trade up. If not, I suspect they possibly trade back and and get option B at QB later in the first, or possibly later rounds.
Either way, there will be a lot of griping around here no matter who they pick. I trust Beane and McDermott, they have a plan and they're acting on it. I think they will be cautious and will not trade up for a "well, he's decent and could work, but not our first choice" guy; there is not room for error given the Bills position needs. I know I'm not introducing anything new and exciting, but I think this is the reality of how the draft will go.