If I understand correctly, this means a flavor of Ubuntu (and Unity, according to the press release) will be used by hundreds of millions of people within the next decade, far surpassing the worldwide market share of Mac OS X, Chrome OS, etc.
In all likelihood, Microsoft now views Ubuntu with Unity as a main competitor on the desktop.
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[1] http://www.canonical.com/content/canonical-and-chinese-stand...
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Edits: changed "few years" to "decade," in response to hydrology's comment (thanks hydrology!); and added a reference to Chrome OS and Microsoft.