The Diamondbacks have dealt middle infield prospect Emilio Bonifacio to the Nationals for reliever Jon Rauch, those putting to rest the bizarre rumor that the Diamondbacks wouldn't give him up to the Pirates for much more valuable players like Xavier Nady or Jason Bay. Bonifacio's not very good--he isn't terribly young for a minor leaguer, and he has no power at all and also lacks the on-base skills to make up for it. Receiving him as the main player in a trade of Nady or Bay would have been a travesty.
Bonifacio for Rauch makes a little more sense, but this is still a great deal for the Diamondbacks. Rauch has been both good and rubber-armed for three years running now (in strong contrast to his early career, when he always seemed to be on the DL), and his control has taken a nice leap forward this year, with only seven walks in 48 innings. His flyball tendencies may cause problems in Arizona--like the Padres' Chris Young, he puts tons of balls in the air despite being one of the tallest players in baseball--but this is still a very good gamble for Arizona, who are struggling with injuries to several relievers.