Kudos to stevenf for running an ad hoc collaboration experiment with SubEthaEdit. See his excellent write up about the results: A Shared Blank Document (aftermath). I see some familiar faces among those who participated. (Hi, Tom!) I'm sorry to have missed the fun, but the results are well-captured and reported.
My favorite observation below. Sad but true:
Just as you can't have walls without graffiti, in a collaborative environment that is wide-open, there will always be destructive behavior. Not to say that it's good or bad... it just is.