For those who missed it, the Unity 4 beta is out this week, which includes working Linux deployment support! This is going to be a huge boon given how many indie games use Unity, and the growing number of large game companies that also work with Unity. The support is looking to be in good shape, and the remaining bugs and snags should be fully worked out by the time Unity 4 is officially released. There wasn't an absolute commitment to Linux from the Unity folks (it was a "maybe Linux support will be in beta quality by release") but it looks like they pulled through and delivered ahead of schedule!
On a very related note, Refract Studios (disclaimer: good friends of mine) have already tested the beta out and announced yesterday that they're committed to having full Linux support for their upcoming multiplayer high-speed arcade racing game Distance - A Next Generation Arcade Racer.
Seriously, just watch that video (and check out the cameos, holy crap!), and tell me you don't want that game. The devs are good folks. Kyle is the single most passionate game developer I've ever met; Jason is an insanely talented programmer who wrote an entire production-quality vehicle physics engine for Nitronic -from scratch-; Jordan has an immense amount of musical and design talent and a relentless drive towards excellence in everything he does. Super amazing awesome people. Also keep in mind that as gorgeous as Distance looks right now, they're still in pre-production and everything you see is still only early placeholder art. It is going to look freaking amazing, and if it plays half as good as Nitronic Rush, it'll play freaking amazing too. (Note that the video was made before the Unity 4 beta, so they only mention Win/Mac in the video, so they couldn't guarantee full Linux support until just this last week.)
Point being, if you care about Linux as a gaming platform, you should send a thank you email to Unity's devs for supporting Linux, and you should absolutely send some cash to the Distance kickstarter to make sure that game happens for Linux users everywhere.
p.s. I am close to a few other teams working on Unity projects, and will be pestering them about Linux support as the opportunity permits. I know most of them aren't even planning OS X support despite Unity already fully supporting that platform, so it'll be a hard sell, but we'll see. Desura and Steam solve the distribution problem on Linux, so there's a lot more likelihood that larger companies will at least give Linux a shot and see how it goes. Obviously many of you know my personal doubts about Linux as a gaming platform, but even I have to admit that things are looking a lot brighter for Linux after the last month or so of announcements. Maybe I'll be proven wrong and Linux will succeed even better than OS X did.