Here's what Shirky himself says about the book:
Here Comes Everybody is about why new social tools matter for society. It is a non-techie book for the general reader (the letters TCP IP appear nowhere in that order). It is also post-utopian (I assume that the coming changes are both good and bad) and written from the point of view I have adopted from my students, namely that the internet is now boring, and the key question is what we are going to do with it.
Yes, as I said: woulda been perfect. Because that is exactly the question of my class, and exactly the question that interests my students. So we have all these cool tools. So what? What can we do that we couldn't do before?
Actually, I think the folks in my class are coming up with some pretty good responses to that question. They're just now working on concept maps to think toward their final projects, and a number of their ideas have me pretty excited.