Nice Open Source smoke screen you have there, Microsoft..
.. shame if someone were to mention Open Standards in public now, would it?
I'll believe that Microsoft has turned a new page in its history when their products start speaking Open Standards. That you need plugins to make Outlook talk carddav and caldav says it all in my opinion, and don't get me started on their ODF support versus MSOOXML. As a matter of fact, LibreOffice has been found to support .docx better than Word, in that it recently was found to handle table background instructions correctly, where as Word actually did not.
So no, still not buying it.