Partially similar to the Android 4.0's Face Unlock feature, Apple's patent is bit more focused towards detection of the user.
Imagine your iPhone talking to you and do things as you say. This would be possible if Apple gets hold of the patent for a face and presence recognition feature in its products using the front facing camera.
Patently Apple gave the Apple's patent filing a detailed overview. As per the filing, Apple's iOS operating system based devices would offer a mechanism to recognise face as well as the presence of the owner.