According to the tutorial, I should go to OpenSSO and download an "express build". However, the download links on the OpenSSO site for the "Express Build 7" appear to require logging in via an account with a paid support contract.
How can one currently download the OpenSSO wars?
You may want to try OpenAM.
I also noticed this.. http://download.java.net/general/opensso/webstartnew/ which will download the bits for testing. And guess what... there is an opensso.war and the like 'in there' that were produced about the same time as the tutorial was written.
I ran in to the exact problem. The builds are not available for free download. I assume it's all because of Sun merger with Oracle. Now I'm worried one day I may have to pay for JDK!!
As mentioned Go and see http://www.forgerock.com/ they provide support and downloads for OpenSSO as OpenAM
Video: http://www.youtube.com/watch?v=_o5ifx4euPw
Also http://www.axiomatics.com/ is a good replacement.