Yes, I have to agree. Though I'm on the Tomcat Users list and read it pretty regularly I still read and enjoyed the Wrox Tomcat book when it came out. I currently have this book out on Safari but have been too busy to look at it. But I will or I'll buy it instead. Maybe I'll do both.
There's a tremendous convenience in having books at hand and there's nothing that makes you a better coder/techie/whatever because you don't waste your time with books. Seems like some sort of backwards tech machismo to me. And I see it all too frequently.
I'm also happy to see someone make a little money from documenting this stuff. There are plenty of books that are a waste of everyone's money but O'Reilly books rarely (but sometimes) fit into that category.