I think Bull since Dwayne Bowe is on a contract year and probably wants to get paid even though I was never a big fan because of inconsistency. With Charles coming back and the addition of Hillis, that running game should open up some opportunities for Bowe.
Keep him..as a WR3 with the upside to produce like a low end #1 WR you got it made if you ask me. You don't really need an upgrade. I would consider jettisoning Moss for another RB with upside (Handcuff if HIllis is available) or a b/u QB. Since you have both Moores that gives you enough depth at WR if you ask me.
What is available in FA?
Maybe try to trade him for an equal WR and a RB handcuff (Mike Bush, Peyton Hillis someone of that nature)