Running a corporate wiki is much different than running a public wiki. People inside a corporate environment expect certain things that (most) public wikis simply don’t have to worry about. These things include single sign on/integrated authentication, WYSIWYG editing, search that finds more than just wiki pages, formalized input, document versioning (draft, stable, published, etc.), document importing, and document exporting.
Thankfully, there are a number of MediaWiki extensions that can provide these types of functionality.