Just a quick FYI that Dan put it on his blog today: http://blogs.msdn.com/b/descapa/archive/2013/08/07/onenote-2013-com-api-xml-schema-onenote-2013-xsd.aspx
If you write any applications that you think might be useful to others, let me know and I can link to them or post them here.
Now, back to testing OneNote.
Questions, comments, concerns and criticisms always welcome,
John