Yeah, quite possibly... I've actually been thinking seriously of rigging up a similar (though less ambitious) project myself so I Googled around to see if it had already been done. (I found a couple posts in different places of people asking if something like this existed, which I think signals interest, but no responses in the affirmative.) I was thinking something along the lines of a regular, well-organized MediaWiki, starting with the basic Alice set or some generic version of it, in which users enter and edit AIML directly. By releasing regular database dumps of the content after running a script over them to delete ill-formed categories, anyone could simply plug the results into their own bot. I'm planning on working on it more this next month, it's a simple enough idea that hopefully I might have something ready to go in May. Of course, it's not nearly as cool as building a wiki environment customized for AIML from scratch, but that's something I don't think I have the time (or technical expertise) for.

Anyway we should keep in touch... yours is an awesome idea and I'm surprised no one has done it yet!