Hi Rob ----

Jim Booth's suggestion leads you the right way on this. For a while, I've been working on the design of a Process Object pattern that was a middle-tier object responsible for launching and monitoring tasks. It would instance a message broker object and then send the broker status messages on the task. The broker would have a UI in some designs or the UI would be designed to work with the broker.

The big issue when you boil it down is designing your framework or architecture to respect a messaging standard and encapsulate that standard into specific objects (brokers, mediators, messengers, et al.) and ensure a set of properties/methods in all other objects that respect the messaging standard. This allows you to focus on what the other objects are supposed to be doing.

I hope this is not too confusing.