As ElDuce posted, the Pirates have indeed recalled LHP Jeff Locke and selected RHP Jared Hughes from AAA Indianapolis. The team also recalled LHP Aaron Thompson, LHP Daniel Moskos and INF Pedro Alvarez and recalled and reinstated Evan Meek from the 60-day DL.
To make room for Hughes and Meek on the 40-man roster, the Pirates moved Paul Maholm and Kevin Correia to the 60-day DL, effectively ending their seasons, and possibly Maholm's Pirates career.
UPDATE by Charlie: Some in the comments are talking about the Pirates' decision not to bring up Gorkys Hernandez and Matt Hague, which we already knew about. These moves probably aren't terribly significant, except in that they suggest that the Pirates aren't huge fans of Gorkys Hernandez and Matt Hague. But Clint Hurdle's explanation made me chuckle:
"We do want to see Derrek Lee (at first base), and I don't need seven, eight outfielders to work through a game. They have worked hard and played hard. You would like to reward them properly. It is quite challenging to get called up and not play. What do you think that does to a player's psyche?"
So Hurdle thinks he's doing them a favor? Somehow, I bet Hernandez and Hague - neither of whom have played in the majors before - would make the best of it. If I were one of them and I were called up, here's what would be going on in my "psyche" for four weeks straight: '#$% yeah, I'm in the majors! WOOOOOOO!!!'