I found this book very disappointing - it is clearly aimed squarely at novices - and I suspect even they would find its patronising tone rather grating after a while. There is far too much 'hey that's cool' and 'congratulations, you're doing really well' for my liking. But, tone aside, the real weakness of this book is that for something called 'Learning XNA' its coverage of XNA can, at best, be described as superficial. The book centres around the development of two simple games, one 2D and one 3D. Nothing wrong with that, except that most of the text is devoted to explaining how these specific samples work and the basic mechanics of creating projects, importing assets and so on, rather than how they use XNA. There is almost nothing about how XNA works or how it makes use of the machine's graphics hardware, and whenever the author gets to some meaty bit of the XNA API, he says something like 'don't worry if you don't understand this [just look how pretty it is]'! Well I'm sorry, but I am worried that I don't understand it - I want to understand it - that was why I bought a book about it!
To be fair, a genuine novice might find some value in this book, but if you are an experienced developer you'd be far better reading the, actually rather good, tutorials on the XNA game creators site.