For the iPod and iPhone, I was not a believer. I eventually came around and have owned several of both. For the iPad, when I heard about it, I was one of the few people I know actually thinking it would sell well and be something I'd eventually want, precisely because I'd been so wrong twice before. That said, it still took me a while to actually want one; my first iPad was an iPad Air. It took until last year for Apple to finally make the thing thin enough, with a good enough screen and good enough battery life. But at no time did I doubt the earlier models would sell like crazy and create an entirely new market, even before it was officially announced.
Same deal with the iWatch. I don't yet know if I want one, though I suspect I eventually will (whether or not I can actually wear one without getting a skin rash remains to be seen, hopefully Apple makes smart material choices). I'm absolutely sure it will sell like crazy.
Other than my metal allergy which is my primary concern, I'm also very much a fan of analog watches. Even if I were to get a smart watch, I would require an overwhelming feature set for me to want to wear the thing every day. And when I dress up and go out, I would probably still prefer a nice analog watch as a fashion accessory. Apple has a tough road ahead convincing people like me to wear one. Will Apple utterly destroy the digital watch market, though, and make piles and piles of money? Sure they will. Lots of people who don't wear analog watches today will be very tempted by what Apple is going to offer.
