Can someone explain how this will work in reality ? So you can leave your iPhone at home... so you will need to have a second sim with a diff number in your watch ? Which you will have to circulate this new number to all your contacts and let them know that you have your watch on and not your phone ? So people will have to try two numbers to get you as they wont know what you have with you. Or will you have to keep removing your sim from your phone and put it in the watch every time you use your watch.
Don’t be silly and watch the the watch section of the keynote