In other news; GlassFish, one of the main representatives of everything Java EE stands for, has not that long ago added the ability to have nested resources. See e.g. Application-Scoped Resources.
Meanwhile, JBoss AS that always had this ability has it taken away.
One small difference between the existing JBoss AS implementation and the GlassFish one is that JBoss AS puts embedded resources in the global JNDI scope, where GlassFish scopes them per module. I would have sworn that I saw some JBoss plans once that would also add this scoping feature to JBoss, but I can't seem to find it anymore.
IMHO, scoping per module would actually work best.