Glass will be held back because most people don't want to look like geeks. Meta's next design looks like it's from an 80's Sci-Fi movie. I'm not trying to be an asshole, but there is no way I could take someone seriously wearing those things.
Don't think about Google Glass / Meta as they are now, think about what happens when they fit on a contact lens...
These devices are going to keep getting smaller and in a few generations will be fairly indistinguishable from a pair of glasses (which many people wear now).
1 - Seriously, look at this guy: http://vni.s3.amazonaws.com/120802142609275.jpg
Like you, I'd never really consider wearing these things in public (or more specifically, in a casual setting when socialising), but I'd definitely consider using them at work/home if I could make them do neat time-saving things that other i/o devices couldn't.
Ultimately, I'm happy to be an early adopter but for me to use them in the public context shown in the video, they'd have to be somehow integrated into something much much smaller. E.g. contact lenses (but that is seriously way off).
Between this, Google Glass and Oculus, we will hopefully see some serious progress in the VR/AR industries.
I'd even go as far as saying the current efforts might be a bad thing for that possibility, if it is even possible, since we might just end up with a patent encumbered wasteland by the time the technology's there.
The 2 things that Glass will have to overcome:
1)The not-so-fashionable look. I'm sure this'll be corrected in the future.
2) The way people feel about a device that may or may not be recording them at any given moment. Let's not even mention anything about a red light glowing during recording because we know that'll be hacked out. Google Glass will be able to record you without you knowing, period. People will simply have to accept that or the product will fail or get banned in so many places it'll almost be not worth owning at all unless you're a hardcore geek. Then of course someone does some super slick mod where Glass just looks like any ordinary pair of glasses; then mass paranoia breaks out and either people get over it or any glasses are banned. ;)
Mind you this paranoia will be happening despite the fact we've had wearable hidden HiRes cameras smaller'ish than a penny for over a decade already... http://www.brickhousesecurity.com/product/b-w+indoor+high+re...
Which makes me wish there was an anti-Glass product out there. Something that makes you disappear, or at least masked as a see-through hologram. It's perfectly acceptable if anti-Glass does not hide your feet for regulatory reasons.
People who are not comfortable being recorded might welcome invisibility as protection.
It's pretty difficult to go out in public without being recorded. Security cameras are ubiquitous.
EDIT: And look at the comment replying me below by user "read" - https://news.ycombinator.com/item?id=6189941 . If we have HN-users who already feel like they need to "protect themselves" against Glass, the general public would be whipped into a frenzy by one FOXNews report.
I don't think this is true. There is already "revenge porn" and upskirt shots from cell phones. Nobody has suggested banning cell phone cameras, or even complained about it in any serious way. (Remeber that law that would require camera phones to always make a noise? How did that go? http://www.opencongress.org/bill/111-h414/show. Out of 435 potentially paranoid Fox-News-loving representatives, he could get no other sponsor.)
I think the whole Glass camera thing is just people trying to rationalize their intrinsic dislike for the thing. (It's new. It looks like glasses. I got made fun of for wearing glasses when I was a kid. They are intrinsically weird.) You can already surreptitiously record pretty much anything that happens in public, and people upload the result to Facebook and YouTube regularly.
ps: It's funny how public react to obvious recording devices when they're surrounded by them.