Microsoft doesn't support the free office fileformat OpenDocument in its Office suites. They don't even want to implement it in the future. The Australian group "Open Source Victoria" (a cooperation of more than 100 companies) wants to change that. They want to develop a plugin to teach Microsoft Office handling with OpenDocument.
The plugin is called "OpenOpenOffice" (short: O3) and is based on the MS-Office filters of OpenOffice.org. It is not yet clear when the plugin will be finished and under what conditions (licence etc.).
Details about the project can be found at http://www.phase-n.com/openopenoffice.
Their motto: "OpenOpenOffice opens OpenDocument documents in Office". If Microsoft will not add OpenDocument to Office, then the Open Source community will do it for them.