Alan Zeichick relates what happened when the first .docx file was sent to BZ Media, a company that runs primarily on Macs. Microsoft says that everything's just swell:

We are running on target and expect to release a free public beta version of the file format converters in Spring 2007, with final converters available six to eight weeks after we launch our next version of Office for Mac (which, as previously reported, will be available 6-8 months after general availability of Win Office.)

But Alan wonders "How can Microsoft expect outside developers to be able to implement these new Office Open XML formats , when they can't even do that themselves in a timely matter? A six to eight month delay, after having more than a year to prepare?"