Steam is a digital distribution, digital rights management, multiplayer and communications platform developed by Valve Corporation. It is used to distribute games and related media online, from small independent developers to larger software houses. Steam also has community features, automated game updates, and in-game voice and chat functionality. - info via Wikipedia
You've probably read lots of rumors about Steam coming to Linux but there was no official word about it. GamesIndustry.biz interviewed Valve's marketing VP Doug Lombardi. The last question was if Valve is working on a Steam version for Linux. Here are the exact question and answer:
Q: Final question, and one I'm sure you're not super-keen to answer, but I promised one of our tech guys I'd ask it. What truth is there to rumours that you're also working on a Linux version of Steam?
Doug Lombardi: There's no Linux version that we're working on right now. ...
So is Valve trying to hide the fact that they are working on Steam for Linux or are they simply not working on it? The rumors must have had a reason (and actually there were many pieces of evidence)! So what's going on? Unfortunately Doug's answer is anything but clear: did they do some work on Steam for Linux and stopped (temporarily or for good), was it a failed test or did they changed their mind and don't want to release Steam for Linux anymore? Either way, it seems we won't have Steam for Linux, at least not for now.
Steam was voted the most awaited Linux project of the year in one of our weekly polls.
You can read the whole interview @ GamesIndustry.biz (you'll be needing an account though, but you can register for free).