You've probably seen the announcement about SteamOS; if you haven't, go Google it for yourself. I'm not your mum.
This is interesting to me because I do like PC gaming. First-person shooters are better with a mouse and keyboard for a start, but also my PC monitor is the only screen in my house that I seem to have control of these days. But also, it reminds me of a time in the dim and distant past, when programmers were programmers and phones were immobile and Doom was the most advanced game ever.
In those days, your standard autoexec.bat file, the one on your 30MB hard drive, would probably load a bunch of TSR processes and run win.com for you. But if you wanted to play Doom, you didn't want all that cruft taking up precious 66Mhz CPU cycles, or chunks of your single megabyte of RAM. So you'd create a boot floppy specifically for playing games, which skipped all the unnecessary cruft.
These days, we just install everything and probably leave it running all the time. Most developers who also use their PC for gaming will have at least one database server running as a service, probably more; plus all the usual system tray cruft. Ever done that thing where you're starting a new AAA game that's pushing the limits of your system, and you right click everything in the system tray and shut it down? Forgetting that you've also got the 64-bit Developer Edition of SQL Server 2008 R2 humming away in the background?
Keeping your gaming environment entirely separate from your productivity environment means you're getting the best performance from your hardware (as long as the historical Linux driver issues are resolved).
So the idea of having a dedicated gaming OS makes a lot of sense to me, and I'd rather it were Valve doing it with Steam than any of the other options. And if I never have to dick around with Origin servers or Games for Windows Live again, I shall die a marginally less bitter and angry man.
For game developers, this new platform should make a lot of sense, too. I have no idea what the overhead is on doing Windows, Mac and Linux versions of a game is, but even if the code is mostly shared, the QA burden must scale linearly. But these three platforms they're targeting are pretty much identical in terms of hardware: x86-64 CPU; NVidia/AMD/Intel GPU; interchangeable PC components. If SteamOS is freely available, and runs well on Mac hardware as well as ordinary computers, there's no reason why SteamOS Linux shouldn't be the only platform you need to target.
Even the faff of switching these days could be ameliorated with a BootCamp type of thing which sleeps the current OS and wakes the other. (Would that work?)
So yeah, bring it on. And I'll probably buy one of those controllers, too. But not for first-person shooters.