I have committed a first version of TreeCache to CVS head. There are 2 new MBeans: TreeCache and TreeCacheView. If you deploy treecache-service.xml, you will have them in JBoss.
TreeCache is a tree-structured cache, check out the javadoc or the source on how to use it. It supports both transient, async repl and async repl modes.
TreeCacheView is a GUI MBean which shows TreeCache in graphical form.
I'll be working on a locking/versioning mechanism now, so that updates to all caches are serialized.
Bela