The paper version of REST in Practice: Hypermedia and Systems Architecture by Jim Webber, Savas Parastatidis and Ian Robinson has now been released.
I was lucky enough to see early drafts of the book give some input on the security sections, and I even got to present some of the material on Jim's behalf in a tutorial at the International Conference on Service Oriented Computing (ICSOC) back in 2008.
In the book Jim, Savas and Ian have drawn from their many years of real-world experience working with Web-based systems and take a very pragmatic approach that is aimed at helping practitioners get their job done. They avoid dogma and strict rules that can be hard to follow when dealing with existing applications and instead focus on making the reader understand the benefits and drawbacks of architectural choices.
The book is also aimed at universities. If you are a CS student trying to get a leg up on your job hunt you'd be wise to read this book. And if you're in academia, the authors even offer up class material to go with the book.
Again, congratulations to Jim, Savas and Ian - the finished book is sure to make a big impact for years to come!