Well, rabbitmq is kind of a pain to get working with it. Additionally, the modules for rabbitmq and mcollective, for puppet, don't really work that well together (read: I had to re-write the ones I found to get them working).
Come to that I'm hoping we can start building out a full set of mcollective modules to replace the existing ones that will be fully supported and kept up to date so that getting mcollective running will be as easy as including a class and waiting.
A huge part of this job is ensuring community patches get merged in and contributors get treated as I would like to be treated when contributing to a project. I hope we can reverse your experience with modules within a few months (I took this job because I've been in exactly your position, grabbing official modules and having them not work at all!)