This book is a collection of essays by several different writers currently working in the game industry, and consequently the results are very patchy. Some of the essays are very well written and interesting, and provide some genuine and practical insight into game design, while others are flimsy, vague and padded to the extreme.
Throughout all of the essays the text is littered with largely redundant references to little-known games and their creators as a lazy way of describing game mechanics instead of actually explaining them. When you couple all the name-dropping and in-jokes with the quality of the actual book, (it looks and feels like somebody produced it using Microsoft Word, clip-art and a home printer, not a good look for a book on design principals) it feels very much as if a bunch of friends got together and decided to compile all their blogs as a way to plug their products.
Ultimately the content doesn't justify the cost or the space of an entire book, and would have been better served by being posted on a website, this seems to be one for obsessive fanboys only.