I don't know if this has been mentioned already, but there is a mailing list about wiki research at large (not just wikipedia research).
wiki-research@wikisym.org
thanks Alain! Do you think the two lists overlap much, though? Though this list is titled 'Research into Wikimedia content and communities' there's a lot of things applicable to non-Wikimedia research; and by extension much wiki research focuses on Wikipedia et al :)
Well, one reason the Wiki Symposium exists is because there is much wiki stuff (research, practice, standards, etc.) outside the Wikimedia scope!
I think some overlap is natural as Wikimedia issues are wiki issues too. However, unless you explicitly change the scope of this list to be generally about wikis and not just Wikimedia related, I'd keep the two wiki research lists separate.
Cheers, Dirk