That does it - I am going to sell my Microsoft stock
From a short term business point of view I can understand why Microsoft might feel that it is necessary attempt to lock in customers with proprietary file formats. I believe that such a policy that is so very much against the interests of their customers is a bad business strategy.
As a stockholder, I wrote Microsoft a letter on this subject early this year. I received no response from them, which I find rude corporate behavior.