I could see a use of not having to have the phone on you while you are home. If they allow everything to work through WiFi, and not just Bluetooth I could some usefulness - not having to run around and find/get your phone to answer it if you have it in the house. My phone is usually in my bedroom or my office if I am at home. I tend not to have it on me. I know iPads can handle calls on the same WiFi network as the iPhone. Perhaps it could work that way in the office too if your phone was on your desk and you were elsewhere.
Perhaps I am in the minority and not wanting my phone on me at all times. When I am home now in the winter I am usually in sweat pants, in the summer in shorts - without the phone. Year round I wear slacks when working, so the phone is usually in my slacks. I have a desktop Bluetooth phone that connects to the iPhone, so I can keep it in my slacks or in my bedroom and still answer it.
