Dennis Kennedy and Tom Mighell present an good primer on wikis for lawyers: The Strongest Links -- Wikis for the Legal Profession.
The big advantage of wikis is being able to produce a notification of change. In particular, the generation of an rss feed and the user having an rss aggregator.
I have been experimenting with wikis for our next generation of our intranet. Wikis by themselves do not offer much more functionality that a folder of documents in our document management system. However, the notification feature of a wiki turns the document into a communication tool.
One area I having testing wikis is for a client's practices and procedures memo. A question came up at a client team meeting: "How will I know when there is a change?" Keeping the practices in a word document would require two steps when a procedure cahnges: (1) the attorney makes the edits and (2) then the attorney has to send out an email alerting others to the change. By converting the memo to a wiki, the two steps are compressed into one. The attorney makes the edits. The intranet then generates the rss feed with the change. Then all of the subscribed attorneys get a notification of the change in their rss aggregators.