Some might, but I think most people will still be using whatever came preinstalled on their computer. And I know that for some people trying to use Linux would be a nightmare. Things that would be simple in Windows turn into a mess that can take days to sort out. (Assuming the issue can be sorted out at all.)
I’ve got computers that can run Linux. (One a dual boot, another a USB Linux dist, and one that had straight Slackware before the HD died.) I actually got and used the Playstation 2 Linux Kit. I’ve got Cygwin in Windows because I prefer grep to windows Find Files and Folders when searching file contents. Back in the day I’ve even done some simple assembly language programming on an Apple IIE. But I couldn’t get my printer working on one computer or get wireless working on another computer. So I don’t think Linux is quite ready for John Q. Public who’s used to autoplay installers doing all the work for him.
And gamers will use the OS that the games they like are available on. (Far as I know UT3’s not available on Linux yet.)