Phoronix has confirmed that Steam is going to be released on Linux:

Direct from the article:
"For those that have doubted the exclusive Phoronix claims for quite a while now that the Steam client and Source Engine are in fact being ported to Linux, the doubts can be nearly laid to rest. Even I began to wonder how long it would take before the clients for their popular games would be publicly released under Linux. However, after confirming the information perhaps a bit too soon, their level of Linux interest is much more clear after spending a day at their offices. A meeting topped off the day with Gabe Newell regarding Linux where he sounded more like a Linux saint than an ex-Microsoft employee. Valve does have some great plans for Linux beyond just shipping the client versions of Steam and their popular games on the Source Engine."

This is awesome for gamers because it gives us a path outside Microsoft and Apple for PC gaming. Many moons ago I played all my games on Linux and it wasn't pleasant. Wine worked spottily on certain games and native game support wasn't widespread. Now that Valve is entering the area I imagine this will change for the better.

I have to imagine this is a front runner for a Steam Box. Reason? If all your stuff runs on Linux, your Steam Box will no longer have a Microsoft requirement and you don't have to license and Operating System to Microsoft for every unit sold. Makes the cost of producing a console cheaper and Valve can do whatever they want with the box itself. Oh and the article says they are hiring Linux kernel folk too.

Step 1: Steam on Linux, a few games run. Step 2: More games run, publishers follow. Step 3: Shop around a new kind of console based on Linux. Step 4: Goodbye consoles as we know them.

You know the Steam Box is all speculation, but the Linux Steam client is real and totally awesome on its own. Cool times ahead for sure.