I remember first hearing about wikis and the fear it sparked in librarians. Anyone can change content! Students will use wikipedia and all of their research will be wrong! I attended a lecture that Jimmy Wales gave at my local library in Florida (he lives in St. Petersburg). He assured the librarians in the crowd that he didn't want students using wikipedia as a "source" for papers. As he pointed out, students (especially in college) shouldn't be citing an encyclopedia as a source anyway.
There was an attempt to start a wiki at the newspaper I worked at in Florida. The idea was for the whole newsroom to contribute to it. There was hesitance from the old-timers and it seemed like only a few people devoted an enormous amount of time to it. Perhaps the time wasn't right. I see the usefulness of wikis and feel that libraries will continue to use them in the future.