OK - I've put an incomplete version of the book online at the Push-A-Button website - http://push-a-button.com/products/books/index.php
You are welcome to download it and have a read. If you like it or find it valuable, PLEASE consider donating, since it takes quite a bit of time to write up a document like this.
It's 150 pages long and goes into much more detail than the blog here. It covers most of the same topics, but in a slightly different way. I've only started on the "Building a Real Life Application" section.
If you want to get rid of the watermark or would like the ability to print/comment etc, if you donate I'll make one available to you.
If you have specific feedback about individual sections of the book (eg. examples that are incorrect, poorly-written or poorly explained sections or just places where it doesn't quite 'work' for you) please sign up to my forums at http://community.push-a-button.com and post on the new "Programming in Vista Media Center" forum.