Microsoft's proposal for the fast track of the OOXML standard was recently shot down by the ISO. Google concludes that Microsoft's OOXML should never be standardized due to things like reliance on proprietary elements and simply not enough time to review the >6000 page document that outlines the standard.
- for a specification of this size, it was not given enough time for review;
- the undocumented features of OOXML prevents its implementation by other vendors;
- dependencies on other Microsoft proprietary formats and their technical defects makes it difficult to fully implement; and
- the overall cost for vendors of implementing multiple standards (hence the lack of OOXML implementations in the marketplace).
If the ISO was to put as much effort into approving this document, it should take them 18 years as opposed to 2 for the ODF standard (which, according to Google, accomplishes almost exactly the same thing). Microsoft is pushing for this redundant standard because it "gives vendors and users a choice" -- however Google rebuts by saying consumer choice is actually damaged by the existence of multiple standards. This is obvious if you look at past examples of incompatible standards that had the same function (ie. Betamax)
I'm not certain if this development actually prevents OOXML from ever becoming a standard, but regardless, it's a huge win for the Open Document Format (ODF).