http://www.phoronix.com/scan.php?page=article&item=steam_confirmation&num=1

The presence of new Linux libraries in Valve's Left 4 Dead client, combined with Valve job listings last year for software engineers to port Windows games to Linux, indicates that a Linux port of Steam exists and is coming soon.

NOTE: There has been no comment from Valve yet, but the news site is trustworthy.

Hell yeah. Not that i would care about Steam, but it's always great to see Linux support.
The internet is the biggest threat to M$ and this isn't the last time we see something like this to happen.

No one else? This is the biggest news in Linux gaming ever, if true.

Awesome!
That would mean I could switch to Linux and still play all games worth playing on PC :)

Great news, Steam is one of the main reason I have a dual boot on my computer.

Nice, mainstream linux support is always welcome. Linux makes me happy because it is choice and competeition, MS will be forced to make a better product to counteract and everyone wins.

Is there already a Mac version of Steam?

Hopefully games released by Valve will have cross-playability online.

If there is one game service that can be highly sucessful on Linux, it's Steam. This would be a huge move for Valve and a more unified PC gaming

It's not open source enough. That means it can never be properly integrated with the rapid pace of distro change. Closed binaries have never worked with the Linux architecture - look at binary graphics drivers or the Flash Player.

Oh, and it's philosophically opposed as well. The only way to make something a standard in Linux is to include it in the distro: distros won't ship closed stuff. Games are just about acceptable since there's no way most games can be made open, but Steam could be opened up.

The ability to play Steam games in Linux would allow me to switch back to Linux again. Hopefully this turns out to be true.