I've got something mostly working with cas as a client. I'm not sure what version it is. One of my colleagues did the direct implementation and ticketing. He also pointed me at links I used to get clues. His server isn't using Seam. The packet I receive contains stuff I use to define roles in my Identity. I can log on and process the packet okay,
I seem to be missing something when I log off because it doesn't challenge me if I enter my application URL after I do what I think is a logoff without closing my browser. Otherwise, it's happy and I'm happy.
I started with a seam-gen'd application and kept pretty good notes about what I did. Let me know if you think that will help.