Not that we'd expect them to
It wasn't long after Valve's Steam operating system was announced that talk of potential exclusives came pouring in. As wild as it would be to see something like Half-Life 3 restricted to the platform, it's not happening. No way. But don't take it from me -- Valve's Greg Comer has told IGN "you won't see an exclusive killer app for SteamOS from us. We're not going to be doing that kind of thing."
"Whenever we talk to third-party partners, we encourage them to put their games in as many places as possible, including not on our platforms," Anna Sweet told the outlet. "Because we think that customers are everywhere, and they want to put their games wherever customers are. That would go against our whole philosophy, to launch something that's exclusive to SteamOS or Steam machines."
Valve's end goal for these initiatives is to make it so changing devices or platforms won't result in lost access to your games or friends. "We're hoping to unify, to get Steam to be as platform- and context-agnostic as possible," explained Comer. "You shouldn't have to shed that every generation, or even slightly shed it."