You guys should make a PHP OOP book, I think it will sell well.
In the past I have bought about 4,5, maybe 6 books on OOP, and none of them got me started CLEARLY. But together they work good! They were all very different. It was hard to pick this stuff up.
So if sitepoint made a book about OOP and diving in, with examples where you create something (not just animals), maybe cover a few patterns, and practice, I think you'd do really good.
It seems like there is a big barrier between procedural and oop thats hard to cross. I think Kevin Yank can do it really good
They already sell one, "The PHP Anthoology" by Ben Balbo, Davey Shafik, Harry Fuecks, Ligaya Turmelle, Matthew Weier & O'Phinney (http://www.sitepoint.com/books/phpant2/).
I personally think that whenever a 3rd edition is done, it should be a follow on to Kevin Yank's BYODDWS taking the simple joke CMS from that book and converting it to OOP and expanding it, possibly taking in MVC as well.