This was the problem with google wave. It tried to solve the distribution problem, but that's easy and solved. The real problem is the opposite, signal-to-noise and information overload.

Also, there is the general problem of keeping information up to date. If every new participant to a conversation has to follow all the convolutions of the original email thread (some of which may be missing because face-to-face meetings probably happened at one point) then that's a huge waste. Figure out how to create a system which naturally encourages people to sum up the current state of the discussion (perhaps with automated aids) and you'll be ahead of the game.