With Valve's very well known "Steam Hardware Survey", after showing some promising Linux statistics at first, last month indicated that the Linux adoption of the game distribution software was stagnate or on the decline. The April figures for the Steam hardware survey are now public and they indicate further losses for Linux gamers...
AMD's drivers still have huge problems, Valve's ports take a bit longer than expected and the #1 Linux distribution Ubuntu is basicly rewriting the whole system at the moment. So this was to be expected.
Although I still think it will be huge two years from now on.
Expected, yes, also because there aren't any fun non-casual games there. I guess not many gamers (the target audience ?) are going to play a couple of old shooters are they ... Or people like me who get motion sickness from shooters and prefer RPGs and RTS games.
Ok fine I really just want to play StarCraft 2.
What I usually hear from gamers would be: "Steam is on Linux now ? Can I play all my games on Linux then ? No ? Then forget it, I'll stick with Windows."
Honestly I think the numbers are ok considering that maybe 1-2% of Steam's content is linux compatible. Steam itself doesn't run poorly and so far every game I've attempted to run in steam (except limbo, which was taken off eventually) has worked, albeit with a little additional effort since I'm using Arch. Valve isn't doing anything wrong, there's just not enough content yet. When Steam for Mac was released, not only did they give away Portal for free but they had a lot of the other source engine games working immediately. With Linux, there's mostly just indie games that people have already played.