I had a look through the table of contents for the book and there looks to be lots of interesting stuff packed in there. Like the chapter on securing a Tomcat deployment for example. I've been involved on projects where having a straightforward guide to locking down a deployment for a production environment would have been very handy!
I'm also interested in the architecture of high profile websites. Do you happen to know of any examples of high profile websites (the sort of sites we all use on a regular basis) that have deployed Tomcat, maybe in a cluster, successfully? I wonder on what basis one servlet container / web server is selected over another.