Various sources are reporting that Microsoft may finally be serious about throwing the full weight of their considerable resources behind OpenXML. I would caution however that opening bubbly might be a touch premature as we still have a long wait until the specifications are deemed complete.
As Jason Brooks of eWEEK correctly points out the success of this format does not rest solely on the fact that Microsoft alone has the power and potential to trigger a large scale consumer level adoption of XML formats. They must also establish the right framework to ensure developers, and particularly those concerned with intellectual property rights can inter-operate with these formats with some reasonable safe guards. It seems the right things are happening, underscored by recognized authorities on thorny topic of open source licensing.
From an XQuery perspective, I say bring it on! Opening up the wealth of information to the power of XQuery can only be a good thing.