as is often the case for books covering the latest IT hype technology, it's tricky to stay abreast new developments. This book, however, differs and manages to distill the essentials out of the useless.
node.js is a new environment and it's not that well documented yet for all its APIs and how things are mixed together from jQuery over npm and nodeclipse, css, html, and I've probably forgotten another bunch of more or less arcane technologies.
One wonders how brittle the IT environments of the future shall be and who will be able to maintain the latest fads; fads being created at today's internet speed. it used to be called software engineering, but has evolved into software banging.