Since Valve released the first stable version of Steam for Linux a year ago, the number of Linux-supported games has grown more than fivefold.
Valve's digital game distribution service now hosts  games for Linux, compared to 60 games last February.
... It's a healthy rate of growth as Valve gets ready to launch SteamOS, the Linux-based operating system for Steam Machine consoles. So far,14 hardware makers have pledged to launch Steam Machines later this year.
But while 541 games is a hefty smorgabord, the catalog still consists almost entirely of games from smaller, independent publishers. Activision, Bethesda, Capcom, Electronic Arts, Square Enix, Ubisoft and 2K Games do not offer a single Linux-supported game on Steam.
Full article and source: PCWorld.
Interestingly I was thinking about this today as well. I look on my Steam installed on Linux, and in my personal catalogue alone, over a third of my owned games now have Linux support (59 out of 130), which is amazing in my opinion.
It's a dying shame that the big publishers seem so reluctant to support non-Windows PC operating systems. Not just for Linux, but for OSX too. OSX certainly has more backing from bigger publishers, but still not nearly as much as Windows. Hopefully this is a situation that will change with the SteamOS launch imminent.
I do think it's very positive though to see so many smaller devs supporting Linux now. Linux users are consistently the highest donors in events such as the Humble Bundle, and to me that's proof that the old "Linux users don't want to pay for software" adage is completely false. It's nice to see that gesture being reciprocated by the developers.
Exciting times for the Linux gaming scene