Linux is an extremely flexible and powerful operating system and I suspect we've yet to truly see it used to full advantage in the embedded world.
One possible reason is that there are many different facets to it and the learning curves can be steep and time consuming. Its possible to figure your way own through the world of Embedded Linux, as I myself have done over the past decade, however I am pleased to see people like Chris putting together books like this which give people a good grounding on many useful topics. I certainly could have used a guide like this back when I started!
I obviously have a personal bias to the Yocto Project, it being my major contribution and attempt to make a difference to the Embedded Linux world. One of its core objectives is to try and make things easier for people building Embedded Linux systems.
We've had some successes; there are also areas we know work is still needed. We're continually trying to simplify barriers to entry and let more people get involved, make the technology more accessible and encourage adoption. In writing this book, Chris is supporting the same objectives.
I hope you enjoy the book, enjoy Linux and that ultimately that we might see you becoming a part of the vibrant open source communities that make up many of the components you're about to learn about.