After using the Gear and Gear Fit and never being a watch lover, I want a smarter device, not a watch. So I want the Gear Fit to become thinner and even lighter so it's unnoticeable when wearing it 24/7, become more rugged, and get a week of battery life.
Functionally, make it track health and exercise automatically 24/7 and more deeply and intelligently know when to pass alerts and when not to (auto sleep mode). Let me be able to respond with more than canned messages and have deep Google Now type functionality (always listening so I can easily set timers, send quick messages, etc when my hands are busy).
Feels like we're still 1.5 years away though there'll be steady progress from now until then.
More out there stuff - in NYC most big stores have NFC terminals - being able to swipe through my loaded cards quickly and having proximity payments would be kind of cool and better than currently pulling out the phone, unlocking it, opening the app, etc. Also being able to use it as my subway/bus pass. Being able to trigger a taxi or Uber pickup with my location automatically sent out and synced to the corresponding app for payment. Very precise deal alerts (MAYBE) by the very aisle you're inside a store - so not random deals when you walk it, but if I'm hovering in the TV section, maybe a deal for just TVs.