I've got "<Set name="statsOn">true</Set>" in my jetty connector config, a StatisticsHandler wrapping my other handlers, and remote jmx enabled (full details below). I can connect to the jvm with jconsole and browse jetty mbeans, though there is no mbean for the connector.
(note that I had to include jetty-jmx.xml as an additional config file when starting jetty in order for any of its mbeans to show up in jconsole, but it's had no effect on hq that I can see.)
the jetty server's jmx.url config prop is set to "service:jmx:rmi:///jndi/rmi://localhost:6969/jmxrmi", and auto-discover jetty ios is checked. when i save the configuration, the agent log reports the following:
2010-04-22 19:22:57,297 INFO [Thread-3] [RuntimeAutodiscoverer] Running runtime autodiscovery for Jetty 6.x 2010-04-22 19:22:57,350 INFO [Thread-3] [RuntimeAutodiscoverer] Jetty 6.x discovery took 0.03