With Peavy and Floyd back, I don't think there is any way Myers comes back. If Floyd is traded, maybe bring Myers back as 4th or 5th starter (if Myers is willing to sign a one year deal -- highly unlikely). The Sox already have Reed, Jones and Crain under contract as righties in the bullpen.
Youkilis isn't worth signing to more than a one year deal and he's likely not interested in that. Seems like he's headed to the west coast (Oakland?) and we hit the re-set button on the Brent Morel era OR move The Tank back to third, sign a FA to play left for a year until our outfield prospects are ready.
A.J.? Would love to see him back for two years, but I think other teams (e.g. NYY) will offer him a three year deal. I think A.J. only comes back if he's prepared to give the Sox a steep home-town discount or JR swoops in at the last minute like he did with Paulie. A.J. seemingly likes playing on the South Side so I suppose it's possible he's back in 2013 -- though unlikely.