If he does do well batting, shop him to a team that needs a first baseman or DH. But we would need to put him somewhere where he can play, and we all know it's not first. 2013 isn't a contending year, so his defense being bad could really only help us in the fact that we could get a high draft pick.
My final point: Let him play anywhere on the field, just so he can get plate appearances. If he does well, look to trade him to a team in need of a 1B/DH. He will suck in the outfield, but he needs to play there in order for him to prove himself at the plate.