Are you seriously going to talk to your watch out on the street and then holding it to your right ear to hear what the other person replies? (when you're wearing it on your left hand that is)
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Who is suggesting you'll have to talk w/ the watch? Do you have to communicate with your iPhone, iPod, or iPad that way? No. The main communication method is touching, tapping, and swiping. I communicate with my FuelBand by pushing a button and the information pops up.
From the details I've heard about the watch it's not an iPhone replacement, it's complementary. It's like a Pebble, but prettier.