I think that what a smartwatch needs to be is as a "companion device" to a phone, and nothing more.
It needs a screen, two buttons (or areas to tap) for "Yes" and "No" and low-bandwidth communication with the phone. The phone tells the watch what to display and what the buttons mean. The watch then needs only to reply with "Message understood, displaying screen", "Yes" and "No". That's it.
All the "killer apps" that a smartwatch could be used for require those things and nothing more.
The Samsung watch and many stand-alone smartwatches are too powerful, too feature-rich and already too bloated. The Samsung watch is already too large to wear comfortably on the wrist. Has anyone mentioned battery life yet? My Casio has a battery life measured in years.