Pivotal Players and Surprise MVP?

The following players will determine the success of the Steelers in 2012, Sure things, like certain veterans and rookie DeCastro will not be mentioned because they are expected to perform well.

Pivotal Players (success will be determined, to a large degree, by the below players stepping up to a new level of performance)
CBs Allen and Brown (2nd and 3rd CBs, respectively?)
LB Timmons (was not very good last year)
DE Heyward (most talented DL on this roster?)
RB Dwyer (Barry Foster II?)
WR Sanders (best route runner, needs to stay healthy, especially given the Wallace situation)
LT Adams (R) (the only tackle on the roster, pending Max Starks being resigned, with a LT skill set)

My pick for surprise MVP? RB Jonathon Dwyer (just have a feeling that this guy will explode if healthy and in shape)