I hope Steam's OS has a bunch of people move over and ditch Windows so that it can finally die. I hate Microsoft almost as much as I hate Apple.
I don't run SteamOS on anything at the moment but I don't think it has a good "desktop experience" since it is intended for gaming.
If they see the light but keep their focus on "gaming" it will get adopted faster. Gaming more or less made the modern computer and pushed its popularity.
I boot windows for games that suck in Linux and won't run without me spending a ton of time on it. When I am lazy I keep windows up because various reasons and such. I don't enjoy it, the UX is crap.
Everything other than my "game system" is *nix only.
If there was a big push to get any program to work on Linux as easily as it does on Windows, it would be over.