He seems to be a nearly perfect addition. LHB, not much power but good AVG (.290ish career vs. RHP) and OBP, looks like he's played mostly 2B, LF, and RF in the majors with a dash of 3B, SS, and CF. I think I saw that he led MLB in pinch-hits last year.
McTaggert twittered that he thinks this increases Bourgeois' chances of making the team. I guess he's thinking they'll start the year with Inglett and Downs as backup IF, and either Manzella or Sanchez at SS. But I wonder if they view Inglett as a possible 5th OF/spare IF type once Keppinger comes back. Then again, Kepp will probably be trade bait as soon as he gets healthy, given his high salary.