WCF - Windows Communications Foundation - represents the vision of tying together all the "stuff" that you may have worked with in the past into a single, unified programmatic API / framework that will provide you, as a developer, the opportunity to build world-class enterprise distributed applications in a Service-Oriented way, and to do so more easily and with more robust qualities than ever before. That's the vision of WCF, and that's why you should be interested in it right now.
I've only met and talked with Juval briefly at a Tech-Ed, during a walk from one presentation to another, but he struck me instantly as the quiet, "Master Mechanic" type. And if you are getting ready to study Windows Communications Foundation (wikipedia) that's what you want.
If you aren't sure what I mean by that -- in my world there are basically two types of book authors - the Generalist, and the Master Mechanic. The Generalist is good at giving you broad-brush coverage of a subject, but they often don't get too much deeper than the basics. On the other hand, the Master Mechanic is someone who feels compelled to tear apart and completely analyze a programming subject or framework. They aren't comfortable just understanding "how it works" - they need to understand everything about how it works, down to the smallest detail, why it works, and why it was engineered that particular way.
You see this in Juval's whitepapers on MSDN, particularly the ones about Generics (which I highly recommend). And, you will certainly see it in this book. You can see the publisher information, table of contents, etc. here.
Programming WCF Services is not a "WCF Basics" book - its a WCF reference. It's brimming with example code and many of Juval's own "helper" classes, and much more. He provides guidance and techniques that go far beyond Microsoft's documentation for WCF and its classes. In addition, Juval notes in his Preface that Nicholas Paldino served as a technical advisor / editor. Anyone who knows Nick and his work, particularly in the C# MS newsgroup, will probably agree that, as an author, one is lucky indeed to have him help with your book. My point is: this book is very well-researched and technically accurate - probably more so than anything else you'll find on the subject.
Mr. Löwy, in his clear and concise writing style, will take you through the basics of Service definition, Hosting, transports, MetaData, bindings, and more as he lays out in great detail each and every facet of the WCF basics. Then he moves on to Callbacks, Transactions, Custom Synchronization, Duplex Proxies, and even more. Each section builds on the previous ones. Juval finishes up with an in-depth discussion of Service-Oriented Frameworks and a Publish-Subscribe service example. There is also downloadable code that accompanies the book, and a WCF Coding Standard appendix.
The bottom line is that this is a book for experts, or those whose goal is to be able to reach expert status with WCF. Windows Communication Foundation is indeed the next generation of SOA communication and service frameworks, and it unifies everything you may have worked with before - ASMX, WSE, MSMQ, EnterpriseServices, Remoting, Transactions, and transports -- all in one cohesive framework that is designed to be easy to learn, easy to use, and totally integrated under the .NET Platform. If you intend to write distributed SOA - oriented applications, you are definitely going to be writing them with WCF- so I'd advise that you get started with it sooner than later!
If you are a beginner, or just looking for the basics of WCF with some example code, this is probably not the best book to start out with - it is simply too technical. There are several other WCF books in the marketplace, and several more coming soon (one of which I am a technical editor for). If you are at the intermediate - to - advanced level with the .NET Framework, I can confidently state after my first reading of Programming WCF Services that it is highly unlikely you will ever see a more complete treatment of this new framework than Löwy's book- either now or in the forseeable future. O'Reilly calls this the "Rosetta Stone" of WCF. They may very well be right.
The book has a sticker price of $44.99, and the publisher also offers a Safari online version. Highly recommended to any programmer above the beginner level who wants to write Service Oriented Architecture (SOA) distributed applications and do it right.