Not that I trust Wikipedia for much of anything, this at least seemed to be somewhat unbiased.
So I think this proves your point that Windows isn't the predominant OS. :-)
The exact google search phrase I used was "number of linux vs windows devices worldwide" which turned up a plethora of links saying Android was #1.
I'm happy to be objectively corrected.
It's almost hard to believe isn't it? Of course, I'm barely willing to really call Android "Linux", even though it is based on the linux kernel and some services. The way most devices are configured just turns me off. I really figure a shell prompt is necessary for a 'real' linux box. I realize you can install bash/sh/ksh, but unless you're willing to root your device, which opens it up to other badness, you really can't do much with it. I pretty much live in X these days, but always have a prompt open for various things.