Based on the running back management of 2011, you'd think both Taylor and Newby will get playing time.
I sure hope not.
The RB position with Ameer and Imani is two-deep and they are, respectively, a junior and a sophomore. Unless one of them get hurt, then you redshirt both Taylor and Newby. That way, the two freshman get acclimated, get stronger, learn the blocking schemes as redshirts and then the next year the distribution of RB's will be ideal (where we then would have a senior, a junior, and two freshman).
By all means, redshirt both RB's unless there is an injury. Or, if Cross turns out to be a role player only (just short yardage) then redshirt one of the two freshman and let the other back up Ameer.