Brian Jones: Office XML Formats : Article on Proposal for Massachusetts to move to OpenDocument: An alternative from Microsoft:
"The Microsoft Office Open XML Formats will work for all those billions of Office documents that already exist today. We are going to provide bulk upgrade converters that allow you to easily convert from the binary formats into the XML formats. Everything that you could represent in the existing binary formats you will be able to represent in XML. This means all features and functionality that people have come to expect from their office products will be stored in XML. This was actually a huge undertaking. The Office applications are very large, and while most people only certain features, each person uses a different set, and in the end all features are used. Trying to lock out those documents and forcing people to lose data and functionality is not really a great idea."