I think Moe will continue to get the majority of the carries until Bennett gets back and/or the end of the season. He's valuable as a blocker and Tice trusts him. Besides, with defenses so concerened about Moss and the O-line opening up big holes, I'd venture a guess that I could get nearly 4 yards a carry (and I'm slow and not particularly quick.)
O. Smith will start getting more of Moe's carries, but I can't see him getting the lion's share. The Vikes are real concerned about protecting Culpepper this year and the coaches aren't sold on Onterrio picking up blitzes.
Don't forget that Doug Chapman will return to the lineup at some point and will get carries as well.
This looks like a RBBC for the entire year unless Bennett comes back and looks real sharp.
Moe remains the most valuable, because even with a healthy Bennett last year he got a lot of TDs.