An incentive-laden one year deal isn't out of the question, but I'm not too optimistic. Sosa was actually doing just fine with Baltimore through the first month of '05, but wasn't the same after he got hurt and missed most of May.
I'd kind of like to see Sosa redeem himself, if only because he was such a beloved figure as recently as a few years ago, and its unfortunate how he's fallen from ambassador to punchline. I don't see a comeback happening, though. I think he's probably done.