Robert Scoble added a comment to my initial Indigo video post and let me know of another one located on the Channel 9 site.  Steve Millet gives a nice overview of Indigo (with demo) which I'd recommend even if you're not interested in learning more about Indigo and just want to know more about security as well as the contract first methodology for SOAs.  You may get a little sea-sick with the camera moving around some during the code demo but it helped keep me more focused. :-)

http://channel9.msdn.com/ShowPost.aspx?PostID=56397