Huh, interesting. Okay, couple of thoughts:

* Under "federation," could you please note the version that this will be introduced in? That way people will know what the barrier is for being able to use it. 
* I think I would say: "Next, we create the exchanges that MCollective needs. In all cases, you will need these two exchanges:" (...exchange example...) "Additionally, if you are federating your RabbitMQ servers, you will need to create a third exchange; be sure to also see the note below under "Federation." " (...exchange example...)
* Does this setting need to be in the server config file too, or is it just for the client? I got conflicting impressions from reading the code/commit msgs and reading the docs.