Does your book address certain issues I have read about, such as problems with JavaScript errors?
From IBM:
http://www-128.ibm.com/developerworks/java/library/j-ajax4/ GWT's run-time libraries are licensed under the Apache License 2.0, and you can use GWT freely to create commercial applications. However, the GWT toolchain is provided in binary-only form, and modifications are not permitted. This includes the Java-to-JavaScript compiler. This means that any errors in your generated JavaScript are out of your control.
[Edit to give a meaningful topic]
[ April 04, 2007: Message edited by: David O'Meara ]