It's 10X easier to find another Yorke than it is another Priester. Priester is arguably a much better prospect, and Yorke doesn't really have a future in Boston. He's redundant, He doesn't have much over the fence power, he's a hit first prospect who hasn't hit in over two years except for the past month, and his defense is fringe average at best. We also have several prospects who will probably make a better second baseman than he will, some with a LOT more potential coming up behind him.
I'd make this trade over and over and over again if I could. Priester might not become a TOTRS, but if you make several moves like this.....one of those guys will.