Microsoft is trying to make it easier for customers to use their file format of choice

Although the Microsoft Office OOXML format has been ratified by both the ECMA and ISO standards bodies, Microsoft is still expanding its coverage of file formats. With a Service Pack next year, this will extend to ODF 1.1 (which is not an ISO standard, but is a market standard), Adobe's PDF 1.5 and the archivally-oriented PDF/A. (Office support for PDF is currently via a download because, hypocritically, Adobe had a hissy fit when Microsoft tried to include it.)

Microsoft says:

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.
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When using SP2, customers will be able to open, edit and save documents using ODF and save documents into the XPS and PDF fixed formats from directly within the application without having to install any other code. It will also allow customers to set ODF as the default file format for Office 2007. To also provide ODF support for users of earlier versions of Microsoft Office (Office XP and Office 2003), Microsoft will continue to collaborate with the open source community in the ongoing development of the Open XML-ODF translator project on SourceForge.net.

Microsoft also says it will support the Chinese national document file format standard, Uniform Office Format (UOF).

The moves will involve Microsoft's participation in a number of committees and standards bodies. It says: "Microsoft will join the Organization for the Advancement of Structured Information Standards (OASIS) technical committee working on the next version of ODF and will take part in the ISO/IEC working group being formed to work on ODF maintenance." The OASIS Technical Committee is currently controlled by Sun and IBM.

Microsoft will also have to change its implementation of OOXML to reflect changes made during its approval as an ISO standard. Microsoft says it "plans to update that support in the next major version release of the Microsoft Office system, code-named Office 14."

Source:  Jack Schofield