This actually came from the Key Equipment Finance wiki. We've found it to be pretty good, but not perfect, in a corporate environment. This addressed point #2, and we've used FCKEditor with pretty good success for #1. Many folks would argue there's a #3 (fine-grained security), but I've managed to hold them off on that front thus far.
David Garard wrote:
I'm still looking forward to corporate readiness of MediaWiki, which for us basically means (1) good WYSIWYG (2) good search. (2) means Lucene in a box. We hardly care what box.
(The competitor is Confluence. Which is highly usable and an UTTER BASTARD to administer. Though Atlassian are very good at support.)
- d.