How about user deployments of well-understood containers (e.g. a war)? That's not in domain.xml, but we provide management capabilities for such things. Although I could certainly see how we'd want domain.xml to be able to express the configuration information for a war, at least the jboss-specific stuff. In such a case, if a user updated the configuration of a war via a mgmt tool, we could persist the update back to domain.xml.