Well everyone will need to wait for real-world tests to be sure, but I'd be quite surprised if they've got it good enough to work when someone is wearing a hat and sunglasses and yet still be secure enough to have a very low false-positive rate.
They generate a depth-map of the face with a pattern projector and IR-camera. Facial bone structure will be unaffected by superficial changes. I suspect things that obscure large portions of the face, like large glasses or a sudden thick beard will give it some difficulties.
That's what the marketing material says. I'd like to wait for some real world tests to determine if this works anywhere near as well as they say it does. My intuition says not, but I'd like to be surprised.
