Large public wiki
A large public wiki like Wikipedia or the Consumerium Content Wiki is going to have special problems managing a whole political spectrum of contributors who see political choice and "hard security constraints" in a great variety of quite different ways.
One issue in selecting wiki code is which group of wiki end users are going to be inclined to contribute, simply because they know that user interface. For instance, using MediaWiki as we do in the Development wiki is likely to attract Wikipedia authors, sysops, etc., which may be good for some things and bad for others.
The sociology and power structure of large public wikis has not been very closely studied. Doing so is a key responsibility of the Consumerium Governance Organization. It probably should begin with examination of the m:faction, m:governance, m:power structure and m:regime change issues on the Meta-Wikipedia, since they've had many problems we haven't yet.