This new Microsoft proposal [.doc] follows the browser ballot proposal, and is quite similar in nature. While the browser ballot was a response to Opera's complaints to the EU about Microsoft unfairly bundling Internet Explorer with Windows, this new document is a response to complaints made to the EU by the European Committee for Interoperable Systems. It contains a number of promises which detail a whole boatload of interoperability commitments in all sorts of areas, from Exchange to Internet Explorer.
Most of the document details promises about interoperability information that should enable developers of all sorts of third party software to more easily implement Microsoft file formats or interoperate with Microsoft technologies.
Quite interesting are the promises regarding Microsoft Office. For instance, Microsoft will make available all necessary interoperability information for not only the file formats in Office 2007, but also the legacy binary formats used in Office 2003 and earlier.
On top of that, Microsoft Office 2010 will include a mandatory dialog for both OEMs and home users that allows the user to select the default file format for Microsoft Office applications. "Beginning with the release of Office 14, end users that purchase Microsoft's Primary PC Productivity Applications in the EEA in both the OEM and retail channel will be prompted in an unbiased way to select default file format (from options that include ODF) for those applications upon the first boot of any one of them."
I made a joke once about BallotOS, but if this keeps on going, my joke might turn out to be closer to reality than expected.
In any case, apart from the file format ballot, this document details a whole load of interoperability pledges and promises to open up Microsoft technologies and file formats, and this can only be seen as a very good thing.