I'm curious, what is it useful for? I've been thinking of getting one since it came out, but can't really imagine what I'd use it for after the coolness of the new gadget wears off.
To provide another data point, I use it to quickly check the weather before heading out, see when my next meeting is, get notified of important messages (such as from my wife), quickly send or respond to messages, track my heart rate and exercise, play music without needing my phone, etc.
My recommendation would be to try it. If you find it isn't useful you can return it, but my bet is that after 2 weeks you'll find it indispensable.
I'm thinking of getting one for a single application - Drafts.
It's basically a take-a-note app. You talk to the watch, it records and transcribes your message, storing it in an application that's similar to an email client. At the end of my day I would open my inbox and process my notes.
I've also been getting into time tracking and I think there are some apps for starting and stopping timers from the watch.
Not to burst your bubble or anything, but as an Apple Watch user I've found that apps on the watch are nothing like you would have hoped: they're slow and limited. I'm not saying that Apple Watch isn't useful–I'm just saying that in my experience, its value comes from things other than apps.
I also have a question: If you are one of those folks that don't use the phone function on their phone often (mostly games and reading and timekeeper while i'm out of the house), and only gets occasional email... is it still useful?
Honestly, they've always looked like a less functional phone strapped to my wrist.