Consider all the PC-only titles. It's safe to assume that many of them make the vast majority of their sales via Steam. If steam promises massive takeup of SteamOS, then it's in their best interests to make them available for it.
From the demand angle, lots of games are console only because they fear piracy on PC versions. But if all these console users are offered a cheap new platform they can use just as easily as their consoles, it's safe to say that many of the users who buy a steambox would start buying games on it too. Console gamers aren't going to suddenly turn into torrent junkies because they wouldn't need to. This would make the PC platform profitable again. And if they start pricing games cheaper, like Steam games are liable to be, piracy would go down even further. Lots of indie PC titles are making money after-all.
Overall, I think once it hits a critical mass it would be a fantastic idea for all parties involved.
From the demand angle, lots of games are console only because they fear piracy on PC versions. But if all these console users are offered a cheap new platform they can use just as easily as their consoles, it's safe to say that many of the users who buy a steambox would start buying games on it too. Console gamers aren't going to suddenly turn into torrent junkies because they wouldn't need to. This would make the PC platform profitable again. And if they start pricing games cheaper, like Steam games are liable to be, piracy would go down even further. Lots of indie PC titles are making money after-all.
Overall, I think once it hits a critical mass it would be a fantastic idea for all parties involved.