We can expect big things from Davey Shafik in the coming months - he's been working on a book for php|architect about one of the more powerful bits of functionality in PHP - streams.
For about 6 months now, I've been itching to write a book on the PHP Streams Layer - one of my favorite features of PHP; and also one of the least known considering it's powerful abilities.
He describes his goal simply as this: to create the definitive resource for working with the streams later in PHP. It should be out sometime in the third quarter of 2008, so keep your eye out for it then.