Penguin Party: Steam On Linux?

So think codey types snooping around in the current closed beta of Steam for Macs. They've found explicit mention of Linux in the launcher, and claim there's no reason for that to be in there if this was purely a Mac thing. Certain, hoofing the Source engine over to OpenGL for Macs makes it platform non-partisan, so there's nothing other than business decisions really limiting Valve from supporting Linux. While there has been previous evidence to suggest Valve have been sniffing around the penguin platform (including a call for a Linux software engineer a few years back), it's merely wild rumours and speculation until the house of Seattle thumps down a mighty hand and proffers answers. There's a really good chance this is smoke on the Unix-water, but it would most certainly be lovely to easily play Team Fortress 2 or L4D on any personal computer.

Who here's using Linux, then? How's the gaming?