Unless you want to stream your PC games and media to your TV, and use the Steam controller. It seems like a perfectly legitimate alternative to PS4 or XBox to me. Perhaps in a couple of years we can play Crysis 4 from the couch on a cheap SteamPad through LAN streaming.
The Steam streaming forums have a lot of people loving it, their whole Steam library playable on their TV with the Steam-controller over WiFi.

Except you can do that without SteamOS, thats a separate feature, Steam Big Picture.

You're almost right, but you're thinking of Steam In Home Streaming.

There are actually a bunch of separate-but-related technologies with Steam at the moment.

SteamOS: basically Steam on linux packaged up conveniently.
Steam Machines: a bunch of high end HTPCs with Steam branding and SteamOS preloaded.
Steam Big Picture: The large screen UI for Steam.
Steam In Home Streaming: The ability to stream games from your gaming pc to another pc over a lan.

Essentially where I see SteamOS making sense is combined with In Home Streaming.

I have my gaming pc. It's a big powerful desktop with lots of cpu and gpu horsepower. I don't give a rats arse about linux or people adopting it, and the games are on Windows, so it's a Windows machine. (I also work on it, so Linux is out of the question). I'm not interested in splitting my computing budget between that and another machine, so there's no way I'm spending $$$ on a Steam Machine.

But buying something small and cheap like an Intel NUC? Yeah, that I can do, and if I'm trying to keep costs down, then saving a windows licence is a bonus. So now I can play low requirement indie games on my TV. Sweet, but I kinda want to play Arkham Knight on my TV instead of my PC. In Home Streaming to the rescue.

I can now play non-linux AAA games on my TV for significantly less than the cost of an XBone/PS4, and not only that, they will look better (none of this 900p bullshit), and I still have my gaming PC for non-controller based games or when my wife kicks me off the TV
It's win all round.

edit: I have no idea if the market for this is big enough to justify Valves decisions, but it works for me, so I'm glad they did it. Plus, everyone laughed at them when they launched Steam....

I feel exactly the same way.

I also think the concept can spread like wild fire. When your friend comes around and see your steam box running hundreds of games from launch, all of which are heavily discounted compared to xbone/ps4, if the controller works well they will be wondering why they ever bought an xbone/ps4 with its limited restricted non-modable expensive games.

Valve has said that if you make a good product its likely people will use it. I would rather have a steam box today rather than an xbone/ps4. More games, cheaper games, better games, older games, indie games, heck ill be running my Atari emulator on it as well.

What I find funny about all this, is that my PC is already hooked up to the TV and I can already stream games to the TV. I have a gamepad and I can already sit on the couch and play my PC games.

But, Microsoft and gpu vendors refuse to fix the issues with display switching that make it an annoying experience. ie audio not detecting, other displays resetting etc.

All Microsoft have to do is streamline the experience, and there is absolutely no need for a steam device.

I think it is already hugely disappointing how desktops / windows are often treated like a gaming environment only. Perhaps I think too much of a developer but using a desktop or windows for gaming ONLY is like getting a gym membership, going to the gym and relaxing in the bar.

@Gavin - most desktops are also a damn bit larger, noisier, uglier and power-hungry than the steam boxes too. Never underestimate how much people care about the external design of their living room appliances.
There's a reason that millions of people have consoles in their living room and desktops in their office.

Yeah, true, that is a big factor. My computer is probably closer to the TV than most people would have because my girlfriend demands the spare room to herself so she can write in peace.

I think what I'm trying to get at though, is that the steamOS / steamBox is more political than anything. Because if you wanted to make a device to play your steam catalog on a TV, and all your other Windows games on a TV, then it would make far more sense to make a sexy / quiet Windows box, develop a console interface for that and then it would be far more capable. I'm not calling it an XBox, because it isn't. That is a far safer bet then gambling on a linux device IMO. I just can't help but think that they have chosen to go that way as a result of a knee-jerk reaction to Windows store, but maybe also to the success of Android. And hoping that they can make their own independent market.

But I for one, as a PC gamer, have absolutely no intention of buying a device that plays games I can already play on my PC, and suffering a power downgrade to boot. And i don't really see any of my gaming buddies moving to any steam platform, other than the Windows version of it.

Anyway it will be interesting to see how much success they have.

I think it is already hugely disappointing how desktops / windows are often treated like a gaming environment only. Perhaps I think too much of a developer but using a desktop or windows for gaming ONLY is like getting a gym membership, going to the gym and relaxing in the bar.

I'm not sure it is viewed as just a gaming platform. Who's viewing it that way? I love the Windows desktop because of the tools I can use such as Visual Studio, 3DS Max, Photoshop. I love it just as much for having those tools as I do for times when I have been really into gaming. Yeah, it's the device on which I've played Starcraft and Battlefield and Witcher, and so many games in the past. But definitely as a development platform, Windows is the best offer.

I run Photoshop 7 etc. for years on Wine/Ubuntu without one single problem. I only need Windows to recompile my apps, so I'm currently looking to get it 3D accelerated in a virtual machine on Linux.

Steam has risks but I would be surprised if it would not succeed. DX and even Windows constantly lose market shares. With OpenGL you can support all OS, hence I'm confident and

looking forward for my next purchase: Project Cars

I think it is already hugely disappointing how desktops / windows are often treated like a gaming environment only. Perhaps I think too much of a developer but using a desktop or windows for gaming ONLY is like getting a gym membership, going to the gym and relaxing in the bar.

... DX and even Windows constantly lose market shares. With OpenGL you can support all OS ...

hah !?

Desktop : There is no other desktop platform other than Windows. Apple and Linux are small sectors of that market but DX and Windows are King. They have not lost there.

Console : DX and Windows have never been in the console market. Though with XB1, i guess you could say DX and Windows are now in that market (kinda).

Tablet : Windows has doubled it's market share 2012-2013 I'm pretty sure. It hasn't been in that market really until recently. So that's growth.

Phone : Yep, Windows has lost market share on phone for sure, at it's peak of around 15%, now down to less than 5%.

So looking at the 4 markets, Windows has both gained and lost market share as the overall market diversifies. But desktop downturn will surely flatten out as the tablet and phone markets stabilize in the coming years. Apple have lost equally in the tablet sector, should we not develop for iPad ?? That wouldn't be wise, as numbers still matter.

People make the mistake of thinking that falling desktop sales mean that the desktop platform (and Windows) is coming to an end. It's really not, it's just that devices more suited to everyday tasks are now available where desktop pc's were the only option in the past. It's completely understandable that desktops become a sub-market of computing devices. But desktop is still a real platform that is necessary and useful as it exists today.

With OpenGL you can support all OS

The problem is that you actually can't.

Mobile platforms don't use OpenGL, they use GL ES, and sure there's some overlap, but it's certainly not just a recompile.

Even despite that you've still got to deal with sound, networking, input, window management, file access, memory management, and other low level services. Use OpenGL and you sure don't get support for those on all platforms.

"OpenGL everywhere" and "use OpenGL and you'll get support for all platforms" aren't just myths; they're lies.