The best Vick in the league will command the lion's share of the carries this year. We'll have 2 fullbacks on the roster, and Williams just got drafted, so he's in as well. Heck, even Allen played some H-back last year.
It's going to come down to Brown or Bradshaw for the last backfield spot, and I'd rather have Brown. This will be the best line he will have played behind, and possibly the best system for him to succeed.