What about WikiExpo? (though I'm not opposed to something with World in it, a la LinuxWorld/MacWorld)
Looking at [[Conference http://en.wikipedia.org/wiki/Conference]], I'm getting a few ideas, but nothing too special. I'll send something in if I think of it.
Ooh! How about WikiSem http://en.wikipedia.org/wiki/Seminar, to go along with WikiSym? Or too similar?