I saw this article today, and wanted to make sure that folks weren't confused about the latest with some of the publishers out there like Science as well as Nature. As I said last week, Murray and I have been talking with them trying to better understand the issues, but the fundamental problem comes down to the fact that these publishers have some very powerful publishing tools they are using that leverage the old binary formats. Those tools do not yet work with the new math functionality in Office 2007, and they also don't work with the new file formats. This is something we're working with them on though, as the new file formats with the custom XML parts and content controls on top (which can provide meaningful structure to the documents) are a great improvement for publishers.
Now to be clear, this doesn't mean that Microsoft Office is "dumped"; it just means that for now if you are using Office 2007, you would just need to save into the old binary format rather than the new XML format when submitting documents to these publishers. When you're using the old binary format, you'll be in compatibility mode which means you'll use the old math editor rather than the new one, so the equations will also still work with their systems.
The article I referenced said this is related to MathML, but that's not really the issue. Office 2007 actually supports MathML. The issue is that when the new math is opened in older versions, it's rendered as a picture, since the older versions of Word don't support all the functionality of the new math in Word 2007. Rather than downgrade the equation, we just render it as a picture so that the customer with older versions can still see the equation as the Word 2007 customer intended it to look.
Murray has more info on this over on his blog: http://blogs.msdn.com/murrays/archive/2007/06/13/getting-word-2007-technical-files-into-publisher-pipelines.aspx