I have about as much hope for Manuel winning a SB as I do for Cyler Miles winning a Heisman. The Bills are making the decision to move on a little early, but it's the right decision. It's just not that hard these days to find a good QB, so there's no reason to stick with a bad one for years and years hoping things will change. And these days, a QB will pretty much prove himself in the very first year. Stories of delayed stardom for guys like Drew Brees, Philip Rivers, and Aaron Rodgers are basically ancient history these days.
Everyone knew Manuel at #16 was a mistake, just like everyone knew Christian Ponder at #12 was a mistake. In the case of Manuel, the Bills got caught up in the flavor of the month mentality. Kaep had just come one pass interference call away from maybe winning it all, and everyone was looking for the next Kaep or Wilson. Manuel is very similar to Kaep, but Buffalo forgot that they didn't have Jim Harbaugh on their coaching staff. So in a way, you could argue it was an ego driven mistake as well.
Buffalo has realized their mistake and I think they deserve credit for at least owning up to it quickly. Some teams with big ego coaches/GMs will still see value in Manuel. Buffalo might get something in a trade this offseason to a team that hopes to copy the 49ers model.