As announced on the Microsoft External Research Team Blog, MS Education Labs in collaboration with the University of Cambridge has released a chemistry add-in for Word (2007 & 2010) that "makes it easier for students, chemists and researchers to insert and modify chemical information, such as labels, formulas and 2D depictions, from withing Microsoft Office Word." It uses the Chemical Markup Language (CML), which is based on XML, and as such should easily allow other technologies to take advantage of the open document format.
Eventually, the developers plan to release a CodePlex version of this project later this year, hoping to build a community around the add-in and increasing the number of molecules available to use. I hope this takes off!
Anyone interested in how it looks and works can head over to the How-To Geek website (which, BTW, is definitely a site you should keep in your RSS feeds) and check out their article Create Chemistry Equations and Diagrams in Word.