I don't know what's actually in the nexus Q, but I do know that when I saw that, my first thought was "oh maybe it's so expensive because they stuck a galaxy nexus in there without a screen" so then I thought about how to accomplish what I wanted with all the old android phones I have... except the old ones can't be updated past certain android software releases, so then I decided I couldn't do better with what I already had, so I wanted a nexus q in every room, but without the built-in speaker/amp so I could hide it inside cabinets.
Edit:
After actually doing some research, at $199, it seems the most interesting solution for me would be to place a docked nexus 7 in every room I wanted audio or other automation in... At least with Google Music, I can upload all my content to the cloud and not have to keep my fileserver running for that kind of media.