From JIRA-474, quoting Jan, enhancements which should be done:
"There is still some more work that could be done. The javabeans properties that are set up on the Jetty6xLocalDeployer should be moved instead into a Jetty6xWAR class to allow the user to supply custom configuration params for the war at deploytime. If there are any questions please ping me."
+add support for JSP 2.1 if applicable (e.g. executing in a JDK5 environment).