Via Tim, Troy Renck writes that he suspects the Pirates will go after shortstop Clint Barmes this winter. Clint Hurdle managed Barmes in Colorado, so it's possible that Barmes would be the rare veteran who might actually be willing to come to Pittsburgh. Barmes has been a very good defensive shortstop for the past several years, so he'd have the potential to help the Pirates even if he didn't hit much.
With that said, I'm not sure he'd hit much. He has a career .637 OPS on the road and has spent his career hitting in the favorable environments of Colorado and Houston. He actually posted a better OPS on the road than at home in 2011, but he's had some pretty huge home-road splits over his career. He'll also be 33 in March, which is a scary age for a middle infielder with a history of trouble hitting for average. Barmes was a full three wins above replacement last season, so it would be a little silly to complain if the Pirates got him, but that depends on the price, and I think the likelihood of him not hitting at all is relatively high.