Despite the LA Times failed experiment back in June 2005 the potential of wikis for news sites has always been there. As was pointed out many times, the problem was largely the choice of editorial material and subsequent lack of oversight.
But since then no one has been willing to follow the LA Times example and give it another shot.
Jimmy Wales makes the obvious point that "The LA Times experiment with a wiki really pretty clearly failed because it didn’t bother to first cultivate a community of users".
I've always thought that a wiki could work really well properly directed at, for example, a fans' view of their sporting club. The history of, say, Collingwood Football Club as written by its supporters would be a great read. The Wikipedia version is OK, but a bit sterile. If an Australian news site could get its act together to encourage Magpies or Rabbitohs fans to tell their stories through a wiki you could get something really powerful working.
Same goes for local history. The old whaling town of Port Fairy on the Victorian coast has a page managed by its historical society and an entry in Wikipedia. Both are unsatisfactory, but a news site could encourage small regional and suburban communities to tell their stories via a wiki. Over time this would develop into great content, as well as being a great way for building engagement with the news brand via a community service.
As Wales says, "if [news sites] think of a segment of the community that it isn't serving well and which it can't serve well because the economics don't work out then this new method of production means they can actually provide a new service."