This looks interesting: Sun Wiki Publisher.
I haven't fooled around with OpenOffice in ages having completely moved to doing pretty much everything using Google Docs. It looks like I'm going to have to kick the tires on this though:
The Sun Wiki Publisher enables you to create Wiki articles on MediaWiki servers without having to know the syntax of the MediaWiki markup language. Publish your new and existing documents transparently with the Writer to a wiki page.
All important text attributes such as headings, hyperlinks, lists and simple tables are supported. Even images are supported as long as they have already been uploaded to the wiki site. An automatic upload of images is currently not supported.
It is the perfect extension for all users who want to make existing documentations and specifications available on MediaWiki servers. Just load the document and call the Extension with 'Send – MediaWiki Server'. A dialog will guide you to publish your document.
Sounds easy enough. I'll let you know how it goes. Now if we just had MediaWiki Markup as an export option in Google Docs... We can hope!