I think they would play Willingham over Milledge in left, absolutely. He's a better player. I presume though, that somebody's going to be dealt, maybe more than one player.
How about trading Willingham back to the Marlins for Bonifaciio, Smolinski and Dean? Sure, it works out that the Nats get Olsen for free, but, since Beinfest is such a blimin' idiot, it would still work out as a better deal for the Fish.