BB/SP need to ask themselves two questions:
Is Dillon worth $4.4M?
Is Maroney ready for upwards of 300 touches next season?
Unless the answers are No and Yes, respectively, then the status - Dillon, Faulk, Maroney, Evans(?) and Mills? - will probably remain quo.
If the answers are No and No, then I think that signing a younger, cheaper Dillon/Antoine Smith-style power back is a good idea. There are some good players available, therefore their prices should be relatively low. I would stay away from Davenport, Davis, Dayne and Green, however.
If the answers are Yes and No, then perhaps a smaller, younger Faulk/Mewelde Moore-style 3rd-down back is the way to go. He could serve as Faulk's understudy/replacement while spelling Maroney on non-short-yardage situations.
The bottom line is: Dillon and Faulk have less games ahead of them, than they have behind them. Their replacements need to be on the Opening Day 53 either this season or next season, esp. in Dillon's case.