The dominant theme is about measurement - mostly that we don't know what to measure.

For me though, these were the "money" paragraphs:

A piece of software isn't just a bag of bits; it's the nexus of a community of developers and users. In the case of open source projects - and increasingly of commercial ones, too - these communities live online. Mailing lists, personal e-mail correspondence, RSS feeds, weblogs, and Wikis are all grist for the social network analyst's mill. By mining such data, this new breed of statistician are able to measure the strength of a person's ties to a community and can assess his or her reputation within that community.

Membership in multiple communities is another potentially valuable clue. In software development as in science, breakthroughs often occur when insights flow across disciplinary boundaries. The conductors of these flows are typically generalists who belong to several (or many) communities and who form bridges among them.

We know intuitively that these are good people to have on your team. Although we can't yet quantify the difference they make, the data, for the most part, is already available for inspection. Perhaps even now another Bill James is making discoveries that will revolutionize what we think we know about the price/performance ratio of software teams.