Despite its age (2007), it's still extremely relevant for any beginner/intermediate WCF programmer. I felt it had just the right level of content, not a "Hello World" and not too advanced. Rather than waste pages on concepts that are used incredibly rarely (such as MSMQ), the author simply says "Beyond the scope of this book", which is the right move, in my opinion. It's well written, easy to follow and helped me go from beginner to intermediate in a couple of days. I particularly appreciated the last section in the book, which summarises the Dos and Don'ts by each topic (Contracts, Clients, Bindings, Security, etc.) Whenever I am designing a new SOA-based project, I shall remember to consult this best practice section.
The only reason why I'm giving it 4 stars is that it's a little old, referencing to .NET 3 and VS 2005. It obviously does not have any information on the competing Web API, for example.
Don't be put off by this though as it's still a fantastic book for anybody who'd like to learn or sharpen their WCF skills.