Windows Hello on the PC, requires extra hardware (a sensor). As for Continuum it will need a new phone with the supported feature from how I read about it.
It's based on hardware to get it to work so current models will not support it as I understand. Someone correct me if I am wrong.
I have an ICON, it's the flagship WP device as of now (along with the 930), and I don't foresee getting it on this phone, although it would be cool if it could.
No, a L640 will get neither, nor will any other currently available phone. You'll have to wait a few more months if those features interest you.
For Continuum the GPU must be able to drive two displays simultaneously, which AFAIK no currently used SoC can do.
Windows Hello encompasses a set of biometric authentication methods. Facial recognition, iris scanning and fingerprint sensing are all parts of Windows Hello. All of them require sensors no current WP device has.
It's true that facial recognition COULD be done with any old camera.Well, Facial recognition is/can be done by software, so it COULD be possible.
It's true that facial recognition COULD be done with any old camera.
HOWEVER! MS' technique relies on infrared light, which is used to recognize the structure of your face beneath your skin. The idea to protect against the simple exploit where a picture is held in front of your device's camera. This obviously requires the ability to emit infrared light and a camera that is sensitive to it. That is not possible with any old camera, and that's why even this part of Windows Hello requires dedicated hardware/sensors.