Code found within the iOS 7.1 SDK suggests that Siri is headed to the Apple TV in future. Pierre Blazquez first found the reference on Friday. 9to5Mac has since confirmed that the code does exist in both iOS 7.1 and iOS 7.1.1′s files. The reference does not exist in 7.0.6.
The file is a supporting property-list resource for Assistant (Apple’s internal name for Siri), containing information about the feature. The UIDeviceFamily array declares what platforms are compatible with the feature.
As shown by Apple’s documentation, ’1′ and ’2′ represent the iPhone/iPod touch and iPad families. The ’3′ represents the Apple TV family.