In one of the first reviews that I've seen of this book, phpClasses.org has posted a new summary and review of the new book - Advanced PHP Programming from SAMS by George Schlossnagle.

"Advanced PHP" is a book that focuses on (these) advanced aspects of developing applications with the PHP language. Besides the advanced PHP features, it also covers advanced techniques that are not specific to PHP but permit developers to make the most of Web application environment.

It seems like this review is very favorable towards this book, and seems like it might just be worth picking up -> Amazon or Barnes & Noble