Jon Udell talks with the Microsoft architect in charge of Office’s XML capabilities:
Word 11 can save formatted documents in an XML format called WordML, or it can save schematized data without formatting as generic XML. Although these two modes are both standard in their use of XML, they are nevertheless quite distinct from one another. In the latter case you use XSLT to apply the WordML styling to a core of pure structured data, but it's optional.If this is accurate, it is *huge*. If MS is indeed going to standardize Word's file format, and use XML no less, it means we no longer need Word. Yes, that's right folks - Word-formatted documents for everyone. Of course, it remains to be seen if MS will open the schema...I'm kind of thinking that they have to, that is, at least have a copy on the local machine. But who knows? They could wrap some nasty licensing around it :(
Read the full article for more tidbits about the InfoPath application, which is where most of the XML-ey stuff will live.