Microsoft is looking to make its own open-document format, OOXML, seem more appealing to the world. They have recently announced a series of enhancements to the standard that seek to increase compatibility between other documents, particularly with documents created under the competing ODF standard.
This week, the company introduced a plug-in for Firefox that allows OOXML documents to be viewed within the browser, removing the need to first download a file. They've also introduced a new SDK for Java development, more "translator" tools that include new templates for creating ODF-compatible documents and better compatibility with ODF in general.
You can easily see where critics will lead with this. Microsoft in the past has been accused of "Extending" a standard, only to make their now unofficial standard de-facto and leave other companies who actually conform the original standard in the dust. Whether or not that is a tactic they plan to use with OOXML remains to be seen, though as it stands right now ODF has a better adoption rate than OOXML does.