Ohman, 33 in August, has a 3.30 ERA, 8.7 K/9, and 5.4 BB/9 in 30 innings this year with three home runs allowed. He came a long way since signing a minor league deal in February, even spending a few days as the Orioles' closer. He hasn't displayed any special ability to retire lefties since the '08 season.
Vanden Hurk seems an acceptable return for two months of Ohman. This year at Triple A he posted a 4.68 ERA, 8.0 K/9, and 3.7 BB/9 in 98 innings, allowing 11 home runs. He's had multiple stints at that level and also has 155.6 big league innings under his belt. Strikeouts have been there, but everything else has been an issue (including health). Baseball America ranked Vanden Hurk 13th among Marlins prospects before the '07 season, noting that he was signed at 17 out of the team's Dutch academy. Did you know the Marlins had a Dutch academy? BA described Vanden Hurk as "smart and coachable."
Dan Connolly of the Baltimore Sun first tweeted that Ohman was traded, and Juan C. Rodriguez of the South Florida Sun-Sentinel tweeted that Vanden Hurk was the return.