Wiki's can be a useful adjunct to websites. They can be readily accessed and customised by participants. On the downside, wiki's can be clumsy to navigate and can take some getting used to for the newly initiated. The interface can appear quite 'busy' and the layout is a bit different from the style of websites most people are used to browsing.
I think wiki's could be very useful for CAO's. They could function as a kind of virtual whiteboard and would come in particularly handy at the Bookdesk. For example, BOSS not founds could be added to a wiki; technical issues could be added so staff would know a problem had already been reported and any issues affecting retrievals could be listed. A wiki would be a handy way of communicating between teams and for receiving information. It could complement the email system.
Wikipedia is a great one stop browsing shop for quick answer grabs. Chances are it will become as deeply embedded in popular culture as 'google' and folks will be winning trivia competitions because wikipedia says so...
'Community Consensus'