Peter Amstein’s explanation of the guiding principles behind our support of ODF in Office 2007 SP2.
Why ODF 1.1? We’re implementing ODF 1.1 in our initial release of ODF support. We chose this version because it is the most current approved ODF specification, and because it is the version of ODF that current release versions of most other applications such as OpenOffice also support. We will support ODF in Word, Excel and PowerPoint, using the file extensions .odt, .ods, and .odp. The exact release date for Office 2007 SP2 has not been announced yet, but we expect ODF support to be available sometime in the first half of 2009.