You can see the sample code we used to create the interaction on Thom's Blog.
Code Samples can be found here
We are also starting a development group for developers interested in learning how to use our DVD and Video API to interact with dynamic content such as Virtual Earth. If you are interested in this please join our DVD One group where we'll be sending out more information in the near future. To join please visit this website: http://groups.msn.com/DVDOne
If you have any other questions please let me know.
NetBlender Development Team