Well, I think I've finally got JBossCache actually configured correctly. I can see it in the "jmx-console" just fine. At that point, my Hibernate HAR was freaking out because it was loading before my JBossCache configuration got loaded.
2007-03-14 17:36:28,360 ERROR [org.jboss.system.server.profileservice.ProfileServiceBootstrap] Failed to load profile: Summary of incomplete deployments (SEE PREVIOUS ERRORS FOR DETAILS): *** CONTEXTS IN ERROR: Name -> Error jboss.har:service=Hibernate -> org.hibernate.cache.CacheException: Unable to locate TreeCache MBean under object name [jboss.cache:service=HibernateTreeCache]
2007-03-14 17:16:31,944 INFO [org.jboss.aop.microcontainer.aspects.jmx.JMXIntroduction] Registered MBean jboss.cache:service=HibernateTreeCache
2007-03-14 17:17:08,720 ERROR [org.jboss.system.server.profileservice.ProfileServiceBootstrap] Failed to load profile: Summary of incomplete deployments (SEE PREVIOUS ERRORS FOR DETAILS): *** CONTEXTS MISSING DEPENDENCIES: Name -> Dependency{Required State:Actual State} jboss.har:service=Hibernate -> jboss.cache:service=HibernateTreeCache{Create:** NOT FOUND **} -> jboss.cache:service=HibernateTreeCache{Start:** NOT FOUND **} *** CONTEXTS IN ERROR: Name -> Error jboss.cache:service=HibernateTreeCache -> ** NOT FOUND **
<depends>jboss.cache:service=HibernateTreeCache</depends>