I picked this up over the weekend, and I highly recommend it. It's relatively cheap (10 bucks for me), and it's packed with fascinating (but not too technical) insights into MK.
Essentially, it's all about the ideas that went, and continue to go, into the design of MK. A brief history of DL is provided, before the book goes into sort of a walkthrough of the park.
Each land is covered separately. The writer gives details about how the architectural styles for each land were picked, how they work together, how they transition into other lands, etc. Like I already said, this is not a technical discussion, so anybody can enjoy it. The book talks about things like how the architectural styles on the border of Adventureland and Frontierland were deliberately chosen to be somewhat appropriate to both themes, so the transition is seamless from land to land.
The book is packed with little details like that to explain how the Imagineers work very carefully to maintain consistent, thorough theming in each section of the park. The book is almost surprisingly straightforward in acknowledging that the themes, while based on real world ideas and places, are intentionally distorted and romanticized to appeal to a natural optimism within the park guests.
Of course, there's plenty of talk about the attractions, too, and how they contribute to the stories each land tries to tell.
The layout is basically text with lots of concept sketches for different rides, shops, lands, etc. I like the rectangular shape personally. It makes the book easy to carry around or stuff in your pocket and...I dunno...it just looks "fun."
So bottom line: If you have any interest in the themes that define each inch of the MK and you want to know more about why Imagineers made the decisions they did to bring those themes to life, you should pick this up. Hardcore Disneyites may not learn a lot of new stuff, but the book does a great job of helping present the mindset of the people who make the parks what they are.