I was starting to lose hope with this book. Processing itself is something of a pidgin on top of Java; the notion of deploying applets on the web to show off information leave me nonplussed. After reading Chapter 8, I am enthused again. It explains how to use Processing directly with Java, rather than as a pidgin.
Further, it occurred to me that people largely don't use Processing to deploy Java on the web. Instead, one can render a PDF or sequence of images (also demonstrated in Chapter 8). There's lots of demo video on Flickr and Vimeo showing off Processing projects as well.
All that said, I'm definitely going to see what the limitations of John Resig's Processing.js are once I'm done with this book.