Converting documents to mediawiki markup
There appears to be few existing tools to automatically convert other document formats (e.g .doc, .xls, .ppt). The simplest approach right now appears to be to convert documents into html and from that to convert them to wiki markup as there are good html->wiki converters. Here are some good links.
Saving a relatively simple Word document (no images or tables) to html and then running that through the converter here produced good mediawiki formatting. A document including images, tables, and centered text did not work as well. The images would need to be added to OWW separately, the table also didn't come out quite right and centered text was no longer centered.