I might be misunderstanding what level of integration you are looking for but couldn't you just use http://code.google.com/p/openid4java/ or some other package inside the normal authentication method?

http://labs.jboss.com/jbosssso/ also mentions "Work in progress for the JBoss SEAM Framework integration" but I have no idea of the progress on that one. There might also be other ways using JAAS