Related to TAG-12 (https://jira.jboss.org/browse/TAG-12) and the associated old discussion:
http://community.jboss.org/message/217771
I wanted to revisit the status of this issue with the AS7 release. The main point of the tag issue was: Rationalization of our deployment directory (primarily EAP issue ...to help customers and our own development teams avoid class-loader collisions.
This seems to be essentially captured in the combination of the module system and profiles. I guess a proper resolution would be to document adding a subsystem as well as an application, collection of applications such that the issue of class conflicts does not happen.