There is a time for all good things to come to an end, and the time has come to shut down OpenXmlDeveloper.org.
Screen-casts and blog posts: Content on OpenXmlDeveloper.org will be moving to EricWhite.com.
Forums: We are moving the forums to EricWhite.com and StackOverflow.com. Please do not post in the forums on OpenXmlDeveloper.org. Instead, please post in the forums at EricWhite.com or at StackOverflow.com.
Please see this blog post for more information about my plans moving forward. Cheers, Eric
Per Brian Jones, the XSDs are now available from Ecma for working draft 1.4 of the Office Open XML Formats spec. You can download a ZIP file here, which contains all of them in one package.