killerclick :
So if some developers don't see the business case to develop or at least provide decent ports for Windows now, what makes you think they'll see the business case to develop for Linux? So yes, I think Steam OS will not be a threat to Windows because it will be just a niche and a curiosity, but if it did somehow take off, it would just further fragment the PC (meaning non-console, non-handheld) gaming market.
Fragmenting? Games are already linux-compatible. Steam is
unifying cross-platform play with SteamOS. How is it fragmenting anything? It doesn't require any new hardware. It doesn't require a user to buy a new OS. Steam is steam, whether it's on Windows or on some other OS. Steam-compatible games will still be steam-compatible games, regardless of whether it runs on Windows, or Mac, or Linux. Game developers/publishers already implement linux-compatibility in games
without a major player (like Steam) expressing intent to support linux (until now). Is every game going to have this support from the publisher? No; just like how they already don't. At the moment (and I'm sure it'll change in the future), SteamOS (and steambox) will let people play Steam games that are
already linux-compatible on a system where that person might not want to go through the hassle of installing linux, installing wine, troubleshooting all of the issues that go into it. And don't need Windows for anything else.
A lot of people--Steam as well as game publishers--actually don't like working with Microsoft/DirectX, and things implemented in Windows 8 made them even more upset.