I recently published an article on Flash&Flex Magazine about Flexunit 4 with Test Driven Development. You can download it from here:
http://ffdmag.com/magazine/991-flash-and-mobile-apps-iphone-and-ipod-touch

I decided to use a real life example to help reader better understand FlexUnit 4 and TDD. While trying to come up with an example, I realized that one of my tasks these days is to create and AIR application similar to Adobe MAX Companion AIR Application for a conference I am organizing called FlashAndTheCity. Creating a real application can show you how the process goes in real development and not in a fake example that tries to make everything simple and easy. Creating applications is complex and changes often even as you build your application.

Feel free to download from here and feel free to ping me with any feedback:
http://ffdmag.com/magazine/991-flash-and-mobile-apps-iphone-and-ipod-touch