That lineup doesn't exactly inspire confidence. It's probably not even as good as the one they started last year with (Johnson vs TO, Ellis vs Schobel). I would say that the only clear upgrade is Spiller. The key to the season will be Edwards. If Gailey can get him turned around then the Bills will be OK, otherwise they are sunk.
Just as a random side not that probably doesn't belong in this thread: I watched the replay of the Cowboys - Chargers game on NFLN last night and was studying Philip Rivers. He is less mobile than Edwards and has an slower release as well, but he gets the ball out of there quickly, decisively and accurately. Dallas has a pretty tough pass rush and they were definitely getting through the SD OL, especially the OLBs, but not only didn't they get many sacks, San Diego completed most of their passes against them and moved the ball rather easily. I couldn't help but think that Edwards would get crushed in the same situation due to his indecisiveness (fear?). Gailey has a lot of work to do for him to be a championship caliber QB.