The Spanish wiki has the most participants so far:
http://es.wikipedia.com/wiki.cgi?CambiosRecientes
How about that...some progress!
The German wiki is growing too, but a bit more slowly:
http://de.wikipedia.com/wiki.cgi?RecentChanges
And the Swedish wiki is growing...mainly due to the dogged efforts of Linus Tolke.
I think at this point if someone were to announce these wikis on the appropriate wikis and mailing lists, etc., they'd take off a bit more. Maybe a lot more.
Larry