These always struck me as a fad waiting to die, but I'm not trying to be the usual Slashdot curmudgeon, so I'll ask: what are the killer features of a smart watch?
The best my buddy could come up with who bought an Android one was some mumbling about how its more socially acceptable to glance at texts on your wrist, than to take your phone out.
Killer features would differ from people to people, but this is what I'd love to see assuming the technology were to exist at an affordable price (affordable price, subjective, I know):
e-mail/sms/jabber/slack/infrastructure-devops notifications (be them sound or vibration) - if I need to reply I pull my phone or go to a computer, but at least I'd like to be notified without me having to pull my phone to read (yes, affordable laziness is bliss.)
fitbit-like capabilities to monitor my physical activity and sleep patterns.
pre-programmed purchasing buttons (think Amazon Dash) for common/recurrent items.
pre-programmed ordering buttons in some type of logistics/supply chains
baby/toddler tracking within a given radius.
discrete weather monitor showing chances of rain or heat or whatever.
job search alerts (or any type of alert feed that you might be interested.)
product scanners at a warehouse or store.
Killer features, I think, will revolve around very specific, repetitive, utilitarian tasks. I do not see smart watches taking off as general media consumption devises (not even for music), but as devices that provide convenient and inconspicuous notification of events as well as means to trigger recurring processes.
And that is the key, I think. I don't see smartwatches taking off as media consumption devises, but as programmable notifiers/triggers.
Obviously we can do the later now with smartphones, but a smartwatch is more convenient. It would not work in isolation, but in tandem with a smartphone on a personal level (or as part of a much larger system.)