“Cloud Application Architectures: Building Applications and Infrastructure in the Cloud” by George Reese is more of an Amazon EC2 and S3 user manual than covering Cloud Application Architecture in general.
Having said that I did find that it still did have some good content although in many areas it was very high level. Some diagrams were also missing from my copy.
There was a good Cloud Computing and Amazon Web Services overview. Cloud ROI, Monitoring & Management, and reiteration that Laws need to be considered were also covered, as were development implications, and in particular multiple-server transaction management.
If you want an overview of Amazon Web Services, EC2 and S3 then this book may be right for you.