Last week Manning Publications Co. announced the book 'iText in Action' in the 'Coming Soon' section of its site. Please find more info about the book on the book description page: http://www.manning.com/lowagie/
Don't forget to register if you want to stay informed about the actual release date.
You can also visit this new iText site: http://itext.ugent.be/ to learn more about iText.