Valve's limited beta testing program for its new SteamOS-powered hardware will include a prototype game controller, according to the Steam hardware beta test terms and conditions page.
While the Steam website doesn't provide any specifics about the controller, Valve has previously talked about its plans to provide new types of input for its "Steam Box" and focus on latency and precision. At this year's Consumer Electronics Show, Valve's Gabe Newell touched on the developer's controller plans.
"I think you'll see controllers coming from us that use a lot of biometric data," Newell told The Verge. "Biometrics ... is essentially adding more communication bandwidth between the game and the person playing it, especially in ways the player isn't necessarily conscious of. Biometrics gives us more visibility."
Newell said at the time that Valve was experimenting with touchpads for its controller, and predicted gaze-tracking will "turn out to be super important."
Valve announced earlier today that Steam Machines from multiple hardware manufacturers will be released in 2014. Prototype hardware will go out to 300 testers sometime this year. The developer has one more Steam-related announcement planned for later this week.