Not that I know of, but might be a great thing to do. Could have categories. Would really add some transparency to the whole content creation in general. Can you image the heated arguments' that would arise from someone bringing up sketchup. Might help calm it, who knows until it's done.
I'm sure some content creator circles may already use it to collaborate privately, but the idea of a General Trainz Zoom Group is cool.
Next question. Someone needs to moderate, who? It would be nice if N3V donated this person, otherwise it's just a free for all and will probably fail.
Or some brilliant person will figure out how to moderate it and generate income from ad money, the Google way.
Regardless of all the things I state above, I think this is a super idea.