I have often heard people claiming that wikis provide a set of collaborative solutions out of the box.
Well actually no. I have worked with wikis for about 10 years now and have become less and less impressed each year. Certainly wikis are easy to set up and you can grant access to several people to work on them to produce collaborative information.
The problem is that they are too unformed, no one can really be sure what the final product will be. To say "we will produce a wiki" is frankly to say nothing. You don't know when to stop, you don't know which terms to link and which to not. And as your team works on it the information becomes more and more distributed. Pieces of information because very hard to find and you end up having to use search to find things that should be in a document.
Documents are 5,000 year old inventions. Documents have served to make laws, declare nations, record history, report knowledge and entertain. Document management is brilliant because it uses common controls on documents which are well understood.