The Pirates have signed reliever Jose Diaz, probably to pitch at Altoona or thereabouts. He's listed at 6-foot-4, 300 pounds, which means he should be fun to watch for those of you at Blair County Ballpark next summer. He's posted some reasonably good numbers in Class AA, but he's already 27.
The Pirates also dropped Cristopher Richardson, who had pitched for them in the Dominican Summer League the past two years, and signed Rudy Pena and Gerlis Rodriguez, probably as coaches.
Update (by Vlad): There's a pretty good overview of Diaz in this 2010 piece from the Frederick News Post.