I think Lambo still belongs in the IF. Still shaky in the OF.
Obviously, Lannan isn't going to get the Nats an outfielder, so that's kinda shot. Ankiel should be back soon (I guess we have to cross our fingers on that too), supplying a stopgap in CF. Damon can play a little left, 1B, and provides a decent OBP if he gets back to career norms. Add that he's never played in the NL, and is relatively fresh, I think he could provide well for the team for a few months, becoming a great bench piece once Harper comes up