You're too early on the jboss-translator.xml usage. :-)
I've just added this to MC's Classloading and Deployers project,
and as such has not been part of any AS6 yet -- not even trunk.
I'll try to put this into AS6 trunk asap -- need to do proper releases of both sub-projects,
but meanwhile you can (easily) replace jboss-classloading* and jboss-deployers* jars in AS6 with the matching trunk's.
Once this is in, one can easily declare jboss-translator.xml as part of deployment; in its META-INF dir.
But the actual translator class has to be part of global lib,
since it needs to be available before we actually create the classloader.
(otherwise it would be a chicken-n-egg problem ;-))