This was actually done more than 3 years ago, so it's not exactly news.
I only found about it now, though.http://hbswk.hbs.edu/item/4834.html
These people made a formal mathematical model to predict the market share of Win vs. Linux, while varying a number of factors. They conclude that Windows starts with such a huge install base that will almost always prevail as the strongest player, but linux can "win" the battle if corporations and governments adopt it (and there still is a cost difference between Windows and Linux).
Thus, FUD techniques and giving Windows away for free are two great techniques for MS to keep ahead.
There are many interesting points discussed, and it illustrates the value of starting with a specific model and a scientific approach, rather than speculating in blogs.