In all of these cases you have to consider how you will monitor and control this user-generated information.
While it is true that there are no pre-existing rules on how you should set up and use a wiki, it is up to you and your users to develop a series of policies, procedures, and best practices that work for your wiki.
In a corporate environment, you will most likely need some sort of editorial review and approval process. Even Wikipedia has instituted review and approval processes for its more high-profile pages. You may need someone to monitor recent changes and interact with contributors. That same person may also need to be available to answer comments, make observations, etc.
In a more technical environment you may need someone who can review changes and comments for technical accuracy, relevancy, and other factors that might cause safety, liability, and warranty issues.
Various wikis provide different tools beyond just a recent changes list for content moderators and auditors to use. With some wikis you can set up RSS feeds and receive alerts when specific pages are altered. Some wikis provide daily email digests of activity, email alerts of changes to specific pages, or even the ability to “follow” specific users and monitor their activity.
For example, the wiki used to write this book sends email to me and my editor whenever a page is changed. That way, I can review his edits and comment quickly if I disagree with or don’t understand a particular change, and he can watch my progress as I write.