The article isn't about existing marketshare, it's about the trend in how that marketshare is changing. This is the first time in a LONG time that Windows isn't losing marketshare to Mac and Linux.

That's a fact. The speculative part here is Why. Is it that Windows 7 doesn't suck? For all we know, Microsoft could have a new ad campaign, or had bought a sales lead sheet made of gold.

Time will tell, but I predict this is not a permanent reversal in the longstanding trend.