Starting Drew was the right thing to do in 2004. Long term, It doesn't benefit the Bills to commit to Bledsoe, since he proved against top teams, he folds like a cheap tent and completely loses his poise.
So get Losman the heavy work in the long off-season program and multiple mini-camps, prior to Summer camp. Whether it's the opener or a few games into the 2005 season, Losman should get his shot. Otherwise, just accept losing twice to the Pats and any good team. Plus you can forget the Playoffs. Bledsoe is entering year 13 and will never improve. He'll only get worse.