We've redesigned Blogroots a bit to reflect the book's cover and we've added some more features, including Blogpopuli, a blog filled with TrackBack posts — meaning that whenever someone who uses Movable Type to publish their weblog writes a post they think would make sense for Blogroots, they can notify our site and we'll include a snippet of their post on our Blogpopuli page, with a link back to their site. For more details, see the tutorial on how it works and how to participate.
Also chapter 3, Navigating the Blog Universe is now online for your reading pleasure.