First, LOL with J.Moore's review, the only other review at the time that I am writing this, because I too was pseudo psycho-profiling the author of this book.
I profile Frank Zammetti as single forty something, too much time on his hands, with such a clear and thorough understanding of Dojo that it almost bores him. Hence the peppering with cultural references which I found quite entertaining. The small tangents in the text are definetly not placed there to cover up a lack of knowledge or to add verbosity (as with many other computer texts that I have read)
But beneath the occasional cultural reference (which are generally well thought-out bits of esoterica) there is a solid book and a solid understanding.
As with the J.Moore review, I too found the content of this book very detailed and clear with comprehensive online examples. You only really need to read the first couple of chapters thoroughly and you are ready to go, with the rest of the book a organized reference and a small source of inspiration.
Highly recommended.
[Note: I received this book free as part of a promotion]
[addendum 13 April 2009]
I have used Dojo for a couple of applications, but have decided against using it further. It does a lot, but seems to have a lot of overhead. I have used the color picker and inline editor, and with the color picker in particular there are many HTTP requests to initialize, so I decided to create a color picker myself from JS which worked a lot better than the DOJO one. Dojo is too heavy for me.