Engadget, more interface functionality will be added eventually for the add-on PS Camera and its microphone, and they "hope" to integrate apps with it in due course. However, at launch it seems your vocal cords won't do all that much with this next-gen console.
According to Engadget, new PS4 and PS Camera owners will be able to switch off their consoles using voice commands, as well as open games. The Camera's facial-recognition tech will also work for logging in, but ti's unclear if there are other voice commands that will be available at launch.
In contrast, Microsoft is pushing strongly with its in-the-box voice integration, showcasing the Xbox One's array of quickly activated commands in a 12-minute real-time demo of the user interface. As Engadget notes, Sony' isn't looking to match Microsoft's focus on camera and microphone input at launch, not at all surprising given the Camera isn't included with the PS4, unlike Kinect with the Xbox One.