Don't think that M$ will be quite shaking in their overpriced boots as until someone invents a desktop operating system that software writers start to mass develop for then windows will lead the way.
I have used the alternatives but in the modern working environment if it is not M$ then forget it. Yes there are those who are moving to Linux but I'd rather have a penny for every M$ bit of software that is sold then a pound for all Linux related application sold.
Seems another desperate toe in the water from the ailing Sun.