At this point I feel like our bullpen is our only real need, with Morales hurt, Miller hurt, Hanrahan hurt (and bad) and Bailey inconsistent. That just leaves Breslow and our Japanese imports (plus or minus Wilson) that I'd feel comfortable with in a game. I wouldn't say we'd need a Papelbon, but someone like a Jesse Crain, or another reliable arm (I'd also give Rubby De La Rosa a shot at some ML innings) And Workman for that matter.
I also think we can use a 3B for our offense. I wouldn't mind a combination of Bogaerts/Middlebrooks/Iglesias in the future at 3B and SS, but I don't feel comfortable with Snyder and Holt getting many AB's. I think we could go after someone like Michael Young which could benefit our team at a reasonable cost without changing anything for the future.
I'd love to get a starter but there's literally no point in a starter that isn't better than any of our 5 starters, and there isn't a point in overpaying for a halfway decent starter unless the news on Buchholz is dire, or Lester can't regain his previous status, or if Dempster/Lackey/Doubront get injured/suck. I believe the only point in getting a starter should be to get an elite starter that would be paired with Buchholz (and hopefully a good Lester) in the postseason.