Amazing how quickly the wizzo new thing dates, isn't it? Does anyone refer to weblogs any more? Copyrighted 2008, so this book was probably pitched to the publisher in say 2006/7. Hollywood style: It's The Tippng Point, with added internet! And so a book was created in the time honoured fashion: publicist, publisher, stuff on paper.
Not so new either is Shirkey's central insight. Knowledge is power, more knowledge is more power or at least more democracy. He pads this out with a lot of anecdotes, some you'll have heard before and others that are just boring.
By now (2011) we can see what Shirley missed: the spammers, trolls, single-issue fanatics, conspiracy theorists, scammers, fraudsters, phishers and above all the tendency (surprise, surprise) to make exclusive communities on the net. Just because information travels faster doesn't make it better.
I think I'm going to "defriend" any other books on the sociology of the web in future.