Hell, who cares? He's started on my team for the past 5 weeks, and scores TDs more than any other player I have.
MBIII is a this point an every week no-brain starter. He is the #1 Dallas threat in the red zone by a mile, and if they have a good lead (as they did today), he'll close out the last 1 1/2 quarters of the game. He's still officially splitting carries. Maybe Parcells will give him more, maybe not. But what difference would it really make? 40 more rushing yards?
If you have him, start him every week. Don't think. Just do it.