PS4 launching with limited voice commands
The PlayStation 4 will support voice commands at launch, but it won't be nearly as in-depth as that offered through the Xbox One's Kinect. Rather, the PS4's camera and microphone will support a number of basic commands that allow you to turn off the actual system and open games.
Other than that, there's not too much going on in terms of voice commands. Though some games may support the functionality, none of the system's third-party apps will allow for voice commands. Sony is hopeful that more apps will integrate this in the future, but for now you'll have to use your DualShock 4. And though the actual system can be turned off with voice, you can't wake it up while in standby mode.
Facial recognition using the camera is also limited at launch, being used primarily to log a user in at launch. Players will go through a one-time calibration at start up where the PS4 will take multiple photos of your face at different angles for streamlined identification. Aside from that, it doesn't look like Sony is focusing too much on gesture control of voice commands, at least at lunch.
This could change in the future, but the lack of support at launch makes the PlayStation Eye a very optional purchase.