Duncan wrote an article entitled And Along Came 10...* that talks about at a high-level how we started the codebase behind on10.net and the next version of Channel 9 some of the architectural decisions behind the scenes.  This project, which has encompassed this whole year, has been a very interesting and fun ride.  Two years from now, I can imagine writing a book on the wild ride of what has become of Channel 9 and 10 and how it got there. 

* The title plays off the Channel9 and on10.net (which we're now just calling Channel 10) relationship of which he is a big fan :)