You almost had me...
...until you made your first bullet point, the one about making alternative office apps import and export MS formats 100%. The issue doesn't exist due to a lack of trying; instead, it's probably because the wizards in Redmond keep making 100% compatability with MS formats a moving (and in some cases proprietary) target.
In fact, I'm already starting to see a few .docx attachments in my office email - doesn't do me much good when I'm running OpenOffice in a nearly 100% Linux/FOSS enviroment. Microsoft simply wants to create yet another proprietary format and get so many people using it that it becomes a de facto standard, thereby locking everyone in to their particular office suite (and, by extension, possibly their OS). OOXML is really not that open after all because you need to run Office 2007 to even touch it. How can they even call that an "open" standard while keeping a straight face?
One of the reasons I went the FOSS route was to avoid the insidious vendor lock-in so often encountered with Microsoft products. It will be a cold day in Hell before I go back down that path.
