Ok so you're playing on SteamOS on your TV:

1. How do you group voice chat to your buddies?
2. Can you stream your gameplay like PS4/XONE and *cough* Windows?

If yes - who pays for these services? How far are Valve willing to go down the console services rabbit hole? Could there even be a subscription service with monthly free games?

Good questions, I guess we'll have to wait and see, I don't think they've given any details for these types of services yet. I could see them possibly making their own steam chat service, not sure about streaming though, they'd have to strike some sort of deal with twitch.

Steam already has group voice chat.

Although, nothing is confirmed, these are my guesses:

1. You do it the same as you do now on Steam. Alternatively, because it is Linux, you can install Skype (I think there is a Linux version) and do that.

2. Windows, yes, everything else no. No one knows how much it'll stream, but it'll mostly likely require Steam on the other end.

As for your other questions, I think you should just think of SteamOS as a normal computer running Steam. Nothing else, really.

We all have more questions. There aren't any answers other than the announcement page that's been up on Steam for a week now. Patience grasshopper.

Like others have said, Steam already has voice chat. There are also Linux-based voice chat programs that you should be able to install, given Valve's open platform policy with SteamOS. With streaming, I would have to guess that Valve partners up with Twitch for integrate gameplay streaming. Twitch is already integrated into Origin, Xbox One, and PS4; SteamOS going down this route just seems logical.

Valve is able to get away with giving these online services for free - unlike MS and Sony - for several reasons. MS and Sony take on a huge initial investment before each console cycle. There is console R&D followed by hardware production (which they sell at a loss in the first couple of years). Then there is the running and maintaining of their online infrastructures. Valve doesn't really have to deal any of these burdens. Valve does have to R&D Steam Machines, but they have already said that their hardware will be off-the-shelf PC components. They do not have to go to AMD/nVidia to design custom hardware. It's also being assumed that Valve will go with hardware manufacturers to produce their console. If so, then Valve does not incur the financial cost of producing and selling these machines. Lastly, Valve's open online infrastructure means that they do not need to run servers for every game that is released. Third party publishers and gamers run the majority of online servers for PC games.

@zero_ said:

I wouldn't expect SteamOS to be able to just run any old Linux software off the bat.

I don't think you want the Linux version of Skype anyway; it's pretty unstable, in my experience.

There is a Linux TS client, I have no doubt there is a Linux version of OBS in the works what with it being open source and all.

1. With a microphone? Maybe they can figure out some workaround to have voice chat via SteamOS, independent of a game. That would be cool. Currently I think adding voice-support and a 'party' the way Xbox currently has it would require developers adding support for it into their games, which retroactively would not be feasible.

2. I could definitely see Twitch making an app for the steam machine. Obviously it's a superb way to watch streams. If SteamOS is as open and collaborative as Valve claims I can totally see Twitch trying to add streaming support to this hypothetical app of theirs too. Dota is pretty popular on Twitch after all.

I doubt very much there will be a subscription service. Why would anyone pay to get a select number of free games every month when that same amount can currently be put towards buying games at a discount. The advantage of the current system is that I get to choose exactly what i want to spend that money on as opposed to being boxed in to only a few games.

Valve knows that if the paid option doesn't offer them something new or convenient PC users will choose the free alternative every time. It's the same idea they've competed against for years as a service that sells games on the PC, a platform where getting things for free is trivial .

Steam already has cross-game party text and voice chat built into the standard and big picture overlay. This chat system also features game invites through steamworks enabled games that will jump you directly into the server, lobby or instance of the game your friends are playing. We'll have to see about broadcasting, but I'd be surprised if there wasn't something eventually.