I've tried to implement the custom RevisionListener exactly as you have it in your example, but the components are not found apparently.  Here is the code

public void newRevision(Object revisionEntity) {
       
        Identity id = (Identity) Component.getInstance("org.jboss.seam.security.Identity");
        IdentityRevisionEntity revEntity = (IdentityRevisionEntity) revisionEntity;
        revEntity.setUsername(id.getPrincipal().toString());
}

I get a NullPointerException on the id.  And yet when I look at the debug page, that component definitely exists in the session context.  I've tried to use Component.getInstance() on other components and each time I get null.  I've tried explicitly stating in which context to find the component. Nothing. 

I must be missing something crucial here. Any idea what?

TDR