[citation][nom]edogawa[/nom]People will still continue to use Windows 7 for quite some time like XP, but I can't see Linux becoming anywhere near as big as Windows is for gaming, at least not for years. Windows 9 will likely be a much better improvement of Metro, hopefully. Linux is great and all, but for normal desktop use, it will never be good for consumers, it's to much work to get things installed and so many different flavors; it's just simply not user friendly and simple as Windows.[/citation]
For gaming, I can Linux getting more popular. OpenGL has been technologically superior than Direct3D and easier to program with. OpenGL also doesn't break compatibility. However, the multi-billion dollar company with cutthroat marketing tactics (F.U.D) made sure the open-source software never saw the light of day in mainstream gaming. The xbox 360 is the only console that doesn't support OpenGL, which forced cross-platform developers to use DirectX. However, OpenGL is coming back; surely you've heard of the OUYA and Android, iOS games, popular benchmarking tools like Unigen Heaven, and FurMark; all of these run OpenGL.
For normal use it's quite the opposite. Windows 7 took me six straight hours to get installed and everything set up. Ubuntu, less than an hour and a half. Even if Windows is pre-installed, it still takes quite some time to update out-dated drivers and remove the crap the manufacturer pre-installed in addition to setting up the usual, such as Anti Virus, codecs, Flash, Java RunTime, and dotNET framework. This is one of the very reasons why Ubuntu/Linux has gained so much popularity in recent years; there is very little set up required and most updates are applied during the installation.
Installing software on Linux isn't a strong point, but I'd say it's a hell of a lot easier browsing a catalog and clicking install vs browsing websites, downloading, and running the install wizard. However, catalog organization could use some more work, and installing software outside of that catalog can be a huge pain, especially for new comers; fortunately the catalog has most everything any user would need.
Ubuntu clearly has the ease-of-use advantage, and anyone who's ever used Ubuntu past version 8.04 knows this. It's the unknown and unfamiliarity that makes consumers stray away from it. They want what they're already used to. This is why Windows 8 will change the game in favor of Linux/Ubuntu.