Daniel Guermeur asked me to share some information on this new GAE/GWT book.
As you might know from my GWT blog post about hosting GWT apps you can deploy your app to a simple servlet container like Tomcat. Recently Google App Engine started supporting GWT applications for deployment, so this gives you the ability to use Google's massive infrastructure to deploy your GWT application. There are some things that you will need to do differently however when deploying to GAE vs a standard servlet container, and the book Google App Engine Java and GWT Application Developmentis there to help you though the process of building your GWT application and deploying it to Google App Engine. Through the different chapters of the book you will follow the authors as they build and deploy their GWT app Connectr.