The Alvarez promotion comes as a bit of a surprise, given his obvious problems making contact for the Hillcats, but he's improved his OPS each month this year, and he has 14 homers. Kyle Stark's comments about the promotion might suggest that Alvarez has hit a bunch of line drives right at people, or something like that:
"People typically focus on performance when it comes time for promotions, but we focus on the process and the specific things we're trying to accomplish at each level. Pedro has accomplished those things, in our minds. Plus, the performance actually has been better than the superficial numbers have shown for a while now."
I'm not usually a fan of promoting players before they master their level, but if Alvarez is anywhere near as good as he's supposed to be, he should be able to move quickly. It could just be that he struggled with his average at Lynchburg because no one would throw him strikes; if that's the case, he'll either start seeing more strikes as he faces better pitchers, or he'll have to learn to lay off bad pitches.
Dubee thoroughly dominated the Carolina League and has been worthy of a promotion for several weeks now. He ended up with a ridiculous 53:3 K:BB ratio and a 1.45 ERA.
Molleken will be 25 in August and probably isn't much of a prospect, but he has developed slowly due to a ton of injury issues, and has pitched much better in 2009 after struggling with home runs allowed in 2008. Promoting him is probably a good idea; his pitching at Altoona will tell the Pirates whether there's anything here.
Durham is 26, still doesn't have much idea how to control the strike zone, and isn't a prospect.
UPDATE: The Post-Gazette reports that the Bucs have also promoted Chase D'Arnaud to Lynchburg. Fellow shortstop Jordy Mercer is already there, so it's possible D'Arnaud will play third now that Alvarez is gone. The Pirates have also signed three more draft picks: 11th-rounder Aaron Baker, 21st-rounder Phillip Irwin, and 43rd-rounder Ed Fallon. Baker, a first baseman from the University of Oklahoma, should head to State College. Irwin and Fallon are college pitchers.