The Pebble doesn't seem like a very good device. They have shipped about 70,000 units over the last few months of the 85,000 backers at $150.
It uses an e-ink display to get a few days battery life. It charges with a magnetic power plug on the side:
No touch input, just the side buttons, no real apps yet. I'd say Sony's smartwatch would be a closer fit if Apple was doing something:
UK price is £79 so it'll probably be around $100. It doesn't mention screen size but a 1.5" OLED display would fit. Perhaps someone mistook the supplies to be for Apple instead of Sony. It needs to be charged daily and because it's OLED, can't be easily read in sunlight, which is no doubt why the Pebble went for e-ink. e-ink isn't good for multi-touch though because it doesn't refresh fast enough.
Apple could build it like the old iPod Nano with LCD. It would be good for changing music tracks when out running and seeing notifications but fairly limited usage. The market would be people who own an iPhone because it can't function as a standalone iPod. Without an iPhone, it would basically be a $100-150 digital watch. That's still a big potential audience (> 300m) but it's not obvious how they'd charge it and if a lot of people would be ok charging their watch regularly.
Glasses will probably take another 5-10 yrs to catch on, unless you're an Iron Man suit designer like Tony Stark.
The battery life of Google Glasses is pretty bad it seems:
5 hours average use and with video recording thrown in, just a couple of hours.