I've posted this some weeks ago in "Performance Tuning" bud din't recieve any answer. So I'll try again here.
I using JBoss 5.0.1 GA. Based on http://www.jboss.org/community/docs/DOC-9288 (Section Performance note - Call By Value) i would expect that parameters and return values of calls to a remote Bean are passed by reference if happening in one jvm.
I've written a simple Remote Bean with a Method that returns a DataBean. I've overriden the DataBeans readResolve and writeOject Method do log some Message and it turns a out the bean is being serialized no matter whether org.jboss.naming.NamingService.CallByValue is true or not.