Not for fitness nuts
As someone with a garmin watch (I bought the forerunner model from 3 years ago, 2 years ago- the price plummets when the new models come out), I imagine that the whole Watch thing is aimed at people like me, or at least at people who will use the Watch in the way that I use the garmin.
Not gonna happen. That little garmin has been battered, ducked, soaked, been trodden on, landed on (by my not exactly petite frame and by my bike), scraped, covered in mud, etc, etc. It's still going (albeit with a couple of scratches on the bezel).
Unless Apple have massively amped up the durability for their Watch, it wouldn't last 2 weeks on my arm, let alone 2 months. Even if they have, they've got a mountain to climb to convince me enough for me to risk what I'd have to pay for a replacement before I took it out.
You can't be a company that washes its hands of water damage (pun unintentional) that at the same time tries to push a device that's designed to be worn without any protective covering on someone doing exercise.