As others have said, I agree the Bills will run more this year. I agree that Dorsey will be a bit more compliant with McDermott than Daboll was.
Add in the Kromer factor and the fact that the Bills are carrying Reggie Gilliam, Tommy Sweeney, and Quintin Knox and I think it's very possible Singletary increases his rushing per game by 7.65 yards (130 yards/17 games) and reaches th 1K mark.