Hi Michael,
To answer your questions:
1. The book is all about Liferay development. The purpose of the book is to show developers how to use Liferay as a platform for their web sites.
2. Since the book focuses on Liferay and its many APIs, there wasn't space for integration topics, as I wanted to make sure I covered as much Liferay functionality as possible. But if there's good demand, and the book is a success, I may be able to tackle some of those topics in a 2nd edition.
3. There aren't specific product comparisons in the book; I sort of thought that was the job of salespeople and not me. I'm just a technology guy, and like to write about the technology.
Thanks!
--Rich