One issue that no one is talking about here is the fact that Vick only had a couple days with the offense. They were off on Monday to recover from the game on Sunday then light workouts on Tuesday, full practices on Wed then walk throughs on Thursday. NOW he has over a week to work with the team and his WR's.
Regardless of how much practicing he does, his accuracy and decision making will always suck. We have years of evidence for that. With that said, I think Brown will still get his share of targets and will be fine with Vick. He won't be an absolute super stud but he'll still be low end WR 1 or high end WR 2 (especially in PPR).
Due to the lack of time with the starters, the game plan was to rely on Bell early and often. They limited his passing plays a great deal. One has to think that they will open it up some more as he gets more comfortable. Bell is a stud, but eventually they will have to throw more as D's dare him to beat them in the air.
Bell will get slowed down eventually...
And while we have years of bad decision making, we also have years of him being a very productive fantasy QB. Bad decision making is more a problem for Pittsburgh than it is for fantasy owners.