I have been working with Silverlight for more than two years now and this book is the most comprehensive collection of fast acting recipes yet. It is well organized, thourough, and well sequenced. I find that it is quite helpful both in giving me a fast answer to those difficult solutions that are just beyond my imagination and in explaining how to develop the solution. The numerous examples of how to supply a complex solution using Expression Blend are just one example of this. If I were teaching Silverlight, this is one of two books that I would have the students buy. The other is "Pro Silverlight 4 in C#". Between these two, a real capability to design and deliver Silverlight can be formed.
There is some reuse of previous examples from former books, but it is minimal, and each previously used example has been expanded to give additional depth. I have coverd a winding route since Silverlight 2 in learning how to program this product well. I have designed three websites using Silverlight, one brand new and two others as upgrades from ASP designs. I have as much interest in going back to the limitations of ASP as I would in giving up my WPF programs and going back to Windows Forms. I got stuck designing a flipping page feature for several months that this book resolved in a few hours.
If you are serious in building sophisticated and capable websites, then this is the book for you. I have saved weeks of time in dead end experimentation by using this book and I can't imagine you want to wast this valuable resource either. So, get this book and become an instant expert. I am giving it my highest recommendation.