As stated in the 6696028, we should now get MalformedURLException as of JDK 6 u12 b01.
Problem is that for, some reason, we get a NullPointerException:
Exception in thread "main" java.lang.NullPointerException
        at com.sun.corba.se.impl.orb.ORBImpl.getInvocationInfo(ORBImpl.java:1737)
        at com.sun.corba.se.impl.protocol.CorbaClientDelegateImpl.getClientRequestDispatcher(CorbaClientDelegateImpl.java:143)
        at com.sun.corba.se.impl.protocol.CorbaClientDelegateImpl.releaseReply(CorbaClientDelegateImpl.java:136)
        at org.omg.CORBA.portable.ObjectImpl._releaseReply(ObjectImpl.java:474)
        at org.omg.stub.javax.management.remote.rmi._RMIServer_Stub.newClient(Unknown Source)
        at javax.management.remote.rmi.RMIConnector.getConnection(RMIConnector.java:2327)
        at javax.management.remote.rmi.RMIConnector.connect(RMIConnector.java:279)
        at javax.management.remote.JMXConnectorFactory.connect(JMXConnectorFactory.java:248)
        at javax.management.remote.JMXConnectorFactory.connect(JMXConnectorFactory.java:207)
        at Client.main(Client.java:31)