It has been tried before, anyone remember Loki Games?
I think there is a potential for Linux to become more popular in order to make it a gaming platform. Right now most games I run under Linux are Windows games in WINE, but the average user won't want to mess around with WINE in order to get the games working properly. They have to be native games.
Steam yeah GabeN is having the Source Engine ported to Linux, his goal is to port as many video games as possible to Linux. But others like EA, Activsion, Atari, 2K, etc have to port their video games as well in order to have a Linux gaming revolution.
Anyone remember the Linux based video game console, Indrema? Why did it fail? Companies didn't want to port their video games to Linux. It took too much time and money and nobody could show the Linux marketshare. It is hard to figure out the Linux marketshare because Linux is downloaded and not sold. Many dual boot Windows and Linux. Problem is every PC sold counts as Windows marketshare even if the owner reformats it and installs Linux or something else. Of those who run Linux, how can we figure out how many Linux users want to play video games verses the ones who use it as a server or non-game use?
No the only way to make Linux a video game platform is to give users a legit reason to switch to Linux and keep track of users who switched and want to buy video games and give that to the video game companies to show it is worth while to port their video games to Linux.
Reasons to switch to Linux instead of Windows:
#1 No more need to worry about Microsoft breaking the OS so your games won't work, Linux has a better track record of being backward compatible. So your video games worked on Windows XP but not Windows Vista/7/8? If you are going to have to rewrite the game, might as well rewrite it for Linux.
#2 Windows is bloated, Linux is better as it loads OS features in a module and caches them in and out so that you don't have a bloated system that slows down your game.
#3 Cross compiling, if you use gcc to write the game, it can be cross compiled over different processors for Linux. If you write the game for Windows, well it only supports certain processor types.
#4 Linux is less virus-prone than Windows, your users won't have to worry about viruses stealing their serial numbers, CD-Keys, and their accounts as well.
#5 You have a more stable OS with Linux, you won't get the Internet blogged down due to a bad performing app as you do in Windows, plus you won't have to worry about memory hogs slowing down the system as Linux has a superior memory management model.
#6 APT, YUM, and other updating/installing programs are better than Windows Update plus many Linux distros have their own application stores to buy software from now. Microsoft has never caught up to Linux in these areas.
#7 Your help desk can work through a Linux issue better than a Windows issue because Linux has better scripts and shells than Windows will ever hope to have. Just point the user to a script to download and fix their issue and have them run it, or give them the command lines to type in order to fix the problem.
#8 Your program will run in a better protected environment in Linux because it is better designed, you cannot become more stable than the Linux/Unix model. Less use of hacktools and aimbots because Linux has a better security.
#9 You can create your own distributions of Linux designed for video games. Who needs Microsoft Windows, just roll your own Linux and put your video game store app on it and sell the user some apps and have them download the video games. You can even sell the game as a Linux based LiveCD/LiveDVD to have users try them out without even installing the OS.
#10 Eventually you will learn that the DirectX/Dotnet way is not the best way and Linux has many alternatives to those technologies that work better.