I was pretty sure then to save labor costs, it will be mass-produced in China. Not really sure now. The prototypes and a few initial batch of samples were (/are being/will be) produced in a secret Apple lab anywhere except China?
The watch is months aways. It will likely be March before it ships, which means they haven't begun producing them yet. We get leaks about everything else because they are in the middle of being produced. It's like asking why there are no iPhone 6s leaks.
Production ramp up for iP6 is completely different than Awatch. iP6 sold 10 million on it's first weekend of availability and could end up selling 100M by the end of the year. the iPhone is also Apple's most important device, so there can be no manufacturing issues. Low rate production on iP6 probably started in June at the latest, but probably even earlier. That results in 4 months of production leaks from the 10's of millions of iPhones being produced.
As was mentioned above, with a likely release date of March, we are still ~5 months away from release. Numbers will be much smaller (10M a quarter might be more realistic). Low rate production probably won't even begin for a couple more months. This is likely one of the reasons Apple annouced so early, to avoid leaks.
If am not mistaken just before or a few days right after iPhone 5S was release, there were (Apple self) leaks (only rumors that time) that Apple was also testing phablets or Much bigger (than iP5) sizes of iPhones. iP6 or iPhablet prototypes or schematics were already produced at that time. Excellent self-leaks / hypes for fans to go on buy & enjoy for the last time the classic size / iconic form factor of the iP5s ... As there will be iPhablets coming not for long. The only thing left to be leaked / seen is the actual components inside the Watch which will be covered and discussed to death here in MacRumors (as soon it hits mass-production in those LEAKY plants or will it be leak-free this time as it will be somewhere else more-controlled labs/plants).
Tim Cook/Jony Ive: Screw you, ______ leakers ... World, Here is the Watch!
Good call in not revealing (or guarding that secret) the Watch form factor too early until the last-minute (remember, it had been years in the making). Just look at those over eager, me first ugly copycats (yeah, even the MEH round versions beloved lol by many).