There's been talk of expanding the WCPedia to include (more) fan projects, but I'm not really sure if that's exactly what you're looking for (or what the project is looking for, for that matter.) I don't know of any other wikis, so unless the admins work something out, probably not.
Hmm. Well, yeah, that is the sort of thing I'm looking for; some space to work where people can see what I'm doing.
I suppose there's no harm in asking the admins; worst they can do is say no and make me go somewhere else.