Maybe not the year of the Linux desktop, but instead the year of the Linux set-top-box.
As long as Valve (and ideally other developers as well) make big-name games availale, then I think a lot of gamers would switch to Linux on their existing computer rather than buy a set-top box.
Plenty of people only use their computers for basic web/email/word processing and games and the only thing that ties them to Windows is games. I'm sure plenty would welcome the opportunity to not have to pay for Windows (or have the hassle of pirating it) so long as the games they want to play are available on Linux.
Unfortunately, right now, the choice is lacking. I see Counter-Strike:Source and Team Fortress 2 being the only big-name games. This is disappointing as they were allegedly beta testing with Left 4 Dead 2 which still isn't available on Linux.
Once the other main Source games become available and new games are written with Linux in mind then I can see adoption of Linux for gaming picking up.