You can find an indecsed version of the content from the XNA session (along with lots of other stuff) here:
You can find all the demos here.
Here are links to the some of the code we developed in the session, plus a bonus “coloured cloud” version.
The presentation was firsts given at Mix 11 in Las Vegas. You can find a video of the presentation here.
You can get a free XNA book from here.