My department comprises 5 teams. I lead a cross-team group charged with making our technical documentation available to all teams.
We ended up creating a Wiki Library in our department's Sharepoint site that serves as an index/overview of all of the high-level documentation. Two of the team prefer to use Sharepoint for WYSIWYG editing and familiarity with MS tools. For them we created a sub-site for each team; and each sub-site has as separate Wiki library in which the team is creating more detailed documentation.
The other 3 teams want to use more of the features in MediaWiki (especially categories and semantic markup) to make it easier to organize and find documents. Most of these teams are programmers, so prefer simple Wiki markup (text based ) rather than the MS WYSIWYG editor. (In fact, they often cut content from a highly formatted document, paste it in a simple text editor to strip the fonts, bold, and other visual markup, before cutting and pasting into a simple editor to do semantic markup.)
So our hybrid solution puts the main index in Sharepoint (where management wants it), but allows us to link to the more powerful, full-featured wiki. It's a kludge, but in this world of many links, it works. Now if we can refine federated searching (across all platforms), everyone will be happy! (NOT!)