Back in v2 time, we did think about the possibility of supporting this but there were many implications (including the classloader aspect).
With the more pluggable/extensible deployment framework in v3, it might be possible to support it. You can file a RFE for this and we will revisit it when we plan for the next release. Thanks.
[Message sent by forum member 'hzhang_jn']
http://forums.java.net/jive/thread.jspa?messageID=478308