The successful smartwatch wiill function and look like a normal analog watch with real mechanical hands, except it will be stuffed to the brim with mobile CPUs, Bluetooth, cellular, WiFi,GPS, NFC, accelerometers, heart rate monitor, flash storage, and batteries. Batteries in the watch face as well as throughout the entire wristband. Just cram it with all that modern crap but make it look and function like a watch that an actual normal person wouldn't be embarrassed to wear. A smartphone with everything except for that obnoxious screen.
If that existed, consumers could pick and choose from an infinite buffet of accessory devices that are purely designed for user interaction, while leaving the connectivity and processing up to your headless wrist-mounted computer, which one again, isn't a complete embarrassment to wear.
Your "smartphone" should just be a screen for your wrist computer. Your laptop should just be a bigger screen for your wrist computer, with a keyboard that's also just an input device for your wrist computer. Your television is just a really big screen for your... You get the idea. Good news: you don't even have to own a crappy proprietary IR-based remote that you'll inevitably lose, because your TV UI exists on the handheld "smartphone" screen that passes data to the big screen via the watch computer.
Your wrist computer would have awesome battery life because it's not powering an LCD screen and the whole device can just be packed with batteries. Notice how the Pebble's battery life puts the Apple Watch to shame, and it could be even better without any screen at all. I have a Withings Activite and the battery lasts for months, even though it has bluetooth and a haptic motor.
Your wrist computer can be upgraded and you can still have compatibility with all of your same accessories, giving you the freedom to upgrade each device piecemeal. Drop your handheld "phone" screen in the toilet? Good thing it was just an LCD panel with a WiDi chip so it only cost 100 bucks, and you didn't lose any phone numbers despite not having cloud backup.
Bottom line: Everyone is trying to make the smartwach work as some kind of pale shadow of a smartphone that has a worthless interface, a garbage battery life, and doesnt even functuon as a decent timepiece. Even with all that, you still have to have a smartphone to make it a functional device. As long as tech manufacturers continue to follow that strategy, the smartwach will continue to be an abysmal failure.
Everyone's been looking for the "smartphone killer" and they're hoping it's the smartwach. It will be, but only once we actually let the smartphone die. What does the iPhone 6s / Galaxy [whatever] offer over the iPhone 5 / Galaxy [whatever - 3]? Nothing. Maybe some new color options. Webpages started scrolling smoothly on phones about 3-4 years ago,and since then its been a wasteland of innovation. We're at the "look how many cupholders we have" phase of smartphone advancement.
It's plain that the future is one device, always on your person, impossible to lose, one unified OS, and with an infinite ecosystem of compatible auxiliary interfaces. If the tech giants don't already have their engineers working toward this vision, they should feel shame.
Why does it even have to be a watch? How much processing power and battery life could you stuff into a subtle, tasteful belt? Nobody has any vision.