Neat, but completely unnecessary - now and in the future I feel.
At this point, anyone who has an Apple Watch also has an iPhone. Use the iPhone for FaceTime and any other camera related things.
Plus, the screen is so small, and the speaker is not that great, so would the user experience be any good? My guess is no, and feel most people would use it for a little bit and then go back to their iPhones/iPads/MacBooks for FaceTime etc.
Do we really want cameras on EVERYTHING now?
Now I do like the idea if putting sensors in the bands to help with certain health monitoring, but I think Apple probably will design everything for now in the sensor module on the bottom of the AW. We may get "health bands" with sensors in the next major redesign of the AW, which probably will not be until around 2021-2022.