Microsoft and interop? Microsoft Office 2007 will support ODF!

Microsoft Corp. is offering customers greater choice and more flexibility among document formats, as well as creating additional opportunities for developer and competitors, by expanding the range of document formats supported in its flagship Office productivity suite.

The 2007 Microsoft Office system already provides support for 20 different document formats within Microsoft Office Word, Office Excel and Office PowerPoint. With the release of Microsoft Office 2007 Service Pack 2 (SP2) scheduled for the first half of 2009, the list will grow to include support for XML Paper Specification (XPS), Portable Document Format (PDF) 1.5, PDF/A and Open Document Format (ODF) v1.1.

https://www.microsoft.com/Presspass/press/2008/may08/05-21ExpandedFormatsPR.mspx