Neil is a Ruby developer and deploying many applications in Heroku. His book “Heroku Up and Running” is in early release stage. Most of the contents are ready and hence review has been made.
As like Heroku ecosystem’s simplicity, this book has only 100 pages with 8 chapters.
As a cloud developer, the first chapter “What is Heroku” is bit bored. The second chapter “How Heroku Works” is pretty straightforward, simple and nicely written. A conceptual/flow diagram is the only missing point. Reader has to go with full load of text. The third chapter explains performance and scalability on “Dynos” and Postgres database. It is worth read.
Chapter 4 covers Heroku Regions – Is it that much worth?
Chapter 5 is fully dedicated for Postgres which is helpful for the respective people. It is a good resource.
Chapter 6 starts with deployment best practices followed by “HOWTO”. It is well written.
Chapter 7 and 8 are really much needed for any people who want to deploy their app on Heroku. Neil really puts good effort to on these two chapters to differentiate highly from Heroku manual. 
The book would be even better if it provide some simple samples than syntax examples.
This book gives me mixed feeling but I suggest this book for its chapter 6, 7, and 8.
You can buy this book at http://shop.oreilly.com/product/0636920027409.do