A great source you probably already know about, Wiki URL blacklists, especially the ones edited on a Wiki:
http://moinmaster.wikiwikiweb.de/BadContent http://www.emacswiki.org/cgi-bin/wiki?BannedContent
Not quite sure how these are edited:
http://spammers.chongqed.org/ or http://blacklist.chongqed.org/ http://www.jayallen.org/blacklist.txt
Open source web proxy filter ... maybe willing to share their URL lists? Of course, this is not a spammer list as far as I know, but perhaps it can be used to amplify and verify SURBL whitelist (to eliminate things) or blacklists (to cross-check an addition).
Huge list of URL blacklists:
http://spamlinks.openrbl.org/filter-bl.htm
Worth trying something more elaborate?
Provide the Wiki folks with a better infrastructure for banning URLs used in Wiki spam (which I'm fairly confident will correlate well with email spam).
1. Get multiple wikis to use a standard format for bad content lists, feed into a SURBL-based Wiki blacklist.
2. All SURBL blacklists can be used on supporting Wikis.
So, SURBL gets a new blacklist (the best kind, one fed with a different type of source), Wikis get a much wider blacklist, etc.
Daniel