George Reese’s book doesn’t have the catchiest title, but the book is superb. One thing to keep in mind, it is not a nuts and bolts or howto type of book. Although there is a quick intro to EC2 APIs etc, you’re better off looking at the AWS docs, or Jeff Barr’s book on the subject. Reese’s book is really all about answering difficult questions involving cloud deployments.
We’ve written a lot more on the book. Take a look: Review of Cloud Application Architectures at Amazon.com