Slowly but surely, people are starting to figure out how to take advantage of the vaunted XML capabilities in Office 2003 (esp. Word). Unfortunately, many early solutions revolve around the same admixture of Word templates and Visual Basic widgets that also characterized previous attempts to glean structure and neutral mark-up from earlier editions of MS Office. But the good folks at OSCOM are beginning to work on basic approaches just using XSLT. OSCOM's work seems to mirror other promising attempts elsewhere -- it's becoming apparent that you need to make 3 to 5 passes over WordML to do something useful to it...
Read more about OSCOM's WordXML project