A friend commented to me:
Are we really so lazy that we cannot "take the time" to remove a 4 inch device from our pocket to check the next meeting or see who's calling?"
A new level of convenience turns something old into something new. Remember the move from dial-up to cable/dsl wasn't so much about speed but the "always on" capability. Wanted to look something up? Your computer was already connected. Friction-free use of the internet made the internet feel more useful. Today can you imagine a 30-60 second delay any time you want to use the internet? No, you can't and you wouldn't want it that way.
These new wristwatches have a similar effect. Yes, you can pull your cell out of your pants or purse, but having it on your wrist means not interrupting the flow of what you are doing. I don't have one but I know a few people with Pebble devices. They use it like a remote display for their cell phone: displaying time, txt messages, weather. For about the same price as an expensive watch (or 2x a cheap watch) it becomes a no-brainer.
Of course, tethered wrist-devices are really just a practice run for the industry who is really waiting for components to shrink enough to have a full-fledged phone on your wrist. Right now they're developing market share and trying new things. By the time the industry figures out the what the killer apps are, how the UI should work, and so on, the hardware world will have caught up with them and be ready for a wristwatch that eliminates the need for a cell phone in your pocket.
Which is all we really wanted in the first place.
I have a Pebble. It means my phone can stay on silent the whole time. Also, there's a Ministry of Silly Walks watchface. (I'm not sure which of these things is more important.)