thanks and congratulations - you've started the first discussion :-)
I have just googled for EventAgregator and one of the results is in the Prism framework.
I don't know Prism but the principle could be simmilar. Some components are publishers and some are subscribers. Additionally MCM uses command pattern for asynchronous operations.
Writing "military simple" I mean there is no sophisticated logic in the framework and the configuration effort is minimized. However even a hello world demo requires three layers (UI, component and worker).
1. UI posts a request message
2. Component handles the request and executes a command
3. After the command is executed the component posts a response message
Due to this three step pattern (Message-Command-Message) you can build modular applications of any size. After some exercise you'll see - it's really military simple.
There is an article presenting the hello world.
and a video tutorial if you prefer watching instead typing
thanks againg for your interest ;-)