We discussed Bastardo earlier today. He has one year remaining before free agency, and he's a good lefty reliever who gets lots of strikeouts but has control issues. He isn't a standard LOOGY and doesn't need to be shielded from righties. Essentially, think of him as a slightly better version of Justin Wilson, but with less velocity and fewer years of team control. Bastardo is a serious fly ball pitcher, which isn't the Pirates' usual M.O., but being a lefty in PNC Park should prevent him from getting into too much trouble with home runs.
It's too bad that the Pirates have to give up on Joely Rodriguez, who performed well in the Arizona Fall League this year, but this is a fair deal. Rodriguez has good stuff, but the results he had gotten as a starter in the minors to this point were middling. He might turn well turn out to be just a reliever, and it's far from certain he'll turn out to be anything at all, so getting a year of an established big-league reliever for him makes sense.
We'll see if the Pirates continue pursuing relief help -- with Tony Watson and Bastardo, they probably have enough lefties now, but they nearly signed righty Pat Neshek earlier in the day, so perhaps they'll continue to pursue a righty.