From the "too good to be true" files: Microsoft is opening up its Office 12 file formats and is submitting them for standards approval to Ecma International. We'll get to see the full license for the Office 12 "Open XML" formats on Wednesday on the Office XML Web site. Microsoft won't label its latest move a concession to the OpenDoc camp. But if it's not, what is it? Any conspiracy theorists out there with novel notions of what Microsoft's rationale is for its latest file-format strategy? Sun Microsystems seems to be asking some good questions, from what we hear. We're sure other OpenDoc-backers will be, too.