I'm not a sabermetrician, and I am not really familiar with Dan Fox, but maybe others can comment on how significant this is, and if this writer has any particular interests or areas of expertise. I thought it was at least interesting and a good sign that they are looking for new perspectives. Scroll down to the bottom of the article, and it reveals that the Pirates front office has hired a contributor to Baseball Prospectus.
UPDATE by Charlie: This is pretty interesting. Fox's work with BP has included the development of a system to evaluate fielding that takes into account factors like pitcher handedness. This could be of particular relevance to the Pirates, who have tried to build around left-handed pitching and now have three lefty groundball pitchers in their rotation.