Honestly, I don't see this having any significant impact on the "future of computing" for two reasons:
1. Developing for wide-distribution across different linux distributions is a complete pain in the butt - I know, I've done it - because by their very nature, different linux distros have different things in them. Yes, you could only support certain distros or go for a lowest common denominator, but then you're not really seeing the full benefits of trying to "go linux", methinks. Thus, I think many developers simply wouldn't bother - especially imagine the support calls! Most technical support departments don't even understand how windows works, so good luck getting any help when the game crashes with a random error on your linux box! Evidence: All Introversion games are released with Linux versions, and I have never once managed to get them to run on any of my Linux boxes, and I wasn't even using obscure distros.
2. Different OSes are good for different things and different people.
Linux is an amazing OS, incrediably flexible and powerful, and the sheer level of control that it places on the user is astounding - you can do pretty much anything you want to it, and this is reflected in the quantity of different distros, or make your own! But, this has a drawback: Average PC users are thick. They like Windows because it is familiar, and it tends not to explode too often. Mac users are often an extension of this, Macs are completely locked down: consequently there is no real ability to tinker like in Linux or to a lesser extent Windows, but this also means the less tech-savvy are physically prevented from mucking it up. I guarentee you that if you put most average PC users (even gamers!) infront of a linux box, they'll find a way to screw it up. Again, I am basing this on experience. I had a very nice box running Ubuntu 6.06 (some time ago now), and then I went away for a bit. My father needed a computer temporarily, so I said he could use it and gave him the passwords. When I came back, he'd completely bricked it - he tried to install Windows 95 on it because he couldn't fathom this "linux" thing.
Linux - Techies and Servers. Windows - Average PC users. Mac - Artists and people with too much money.
Now, don't get me wrong, I love Linux, I use it most every day. But I also use Windows, and I love it to. As I see it, they both have their strengths, and I wouldn't want it any other way. I don't -want- a Linux desktop because in my experience, that's simply not what they're good at. Windows is, but as a server system it is rubbish because it's far too locked down and vulnerable.
P.S. Regards the debate on Windows 8, no, I'm not particularly looking forward to it either. They're trying to kill two birds with one stone but will fail to capture either; they need to offer something absolutely amazing to have any impact in the tablet market, which they inveitably won't, and the "Metro" screen will completely ruin the experience on ordinary PCs - and that's even if you DO happen to have a touchscreen hooked up to your PC or Laptop. Chances are you won't, and it'll just be awful. I don't mind them trying to capture tablet market share if they want, but for God's sake leave the "classic" start menu as an option, or I will never, ever buy Windows 8. Period. I would probably even go so far as to wipe it off a new computer and install Windows 7 in it's place if "Metro" couldn't be disabled.
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