That too gives me some serious pause.
I was watching the latest MacBreak Weekly pod cast and they had someone on talking about the Apple watch, and specifically the nike edition. This person happened to be an avid runner and he was not really sold on apple watch for serious runners (as he saw them), and more so for the Nike flavor. They made it a point to mention how annoying the reminders will turn out to be.
I guess for those of us who run, do we really need to be prodded to go out for a run?
As for my running style, I'm generally a solo runner, I enjoy the quiet and solitude of a running alone, and that's another aspect I think where the nike watch doesn't fit my needs. I don't need to know or care of "John Smith" is ahead of me and if I push harder I could over take him.
I'm still intrigued by the nike edition, but as I peel back the onion and see what it actually gives me, I'm less enthusiastic then I was at the keynote.