Gray Knowlton had a great post yesterday laying out more of the details on the "Save as ODF" functionality that will be built in natively for Office 2007 SP2: http://blogs.technet.com/gray_knowlton/archive/2008/05/21/microsoft-adds-save-as-odf-to-office-2007-service-pack-2.aspx
Even though ODF 1.0 is the official ISO version of the format, the decision was made to use version 1.1 which had some accessibility improvements. Hopefully future versions of ODF will be brought back to ISO so that we have a more current ISO version soon. You also may have noticed that we as Microsoft plan to start participating in the ODF standardization efforts, whether that happens in OASIS or ISO.
We hope to work closely with the community to help ensure we make the right design decisions in our ODF implementation. We will focus heavily on interoperability and observe how other products implement the standard, but we will also make sure that our priority one goal is to follow the standard itself. So if there are areas that aren't quite clear in the standard we'll look to other products like Open Office and how they do things. I've heard different opinions though on what to do if the standard says one thing and Open Office does something else. I think the right thing to do is to follow the standard, but I'd be curious to hear what other folks have to say. Doug Mahugh's blog is a great place to start conversations around these types of issues, and I know he'll be posting a lot more material around our design philosophies and areas where we hope to get feedback.
Gray and Doug both blogged yesterday with all the details: