It turns out that although JMX is a mature server-side specification addressing how to remotely monitor and manage a J2EE application, it leaves a lot to be desired in terms of the presentation of that information in a UI - whether it be thin or thick client (HTML or Swing in the Java world).
Various implementations of JMX UIs then leave quite a bit to be desired - system administrators don't manage systems using an MBean concept, they use processes. In addition, I believe that MBeans should be nestable - so that I retrieve a top-level MBean corresponding to my application and then use it to drill-down to MBeans corresponding to specific modules in my application that I want to manage as part of a sys admin process.
I've chosen to go with a regular thin client suported on IE / Firefox for this - I simply don't need Swing and requiring my end-users to install a heavy-weight client such as MC4J plus potentially a JRE just to manage my application is a requirement too far..
