If you put your cell phone away, it goes in your pocket. If you put your Segway away, it goes in the garage (or something?) It's still useful there since you can access it when you need it.
If you put Glass away, you basically invalidate the purpose of Glass itself, which is to be an always-available HUD for your life. (At least as far as I understand it.)
And yes, I agree the only way to know if the public is ready is to release a product. I'm not saying they shouldn't do it but I'm pretty bearish on them being able to pull it off. My gut is that there is a product that exists between "cell phone" and "heads up display you wear on your face" that would have reduced the risk of colossal failure. (Similar to how there is probably a product between "E-Mail" and "Google Wave" that would have worked better too.) There are just too many things that have to go right that have nothing to do with technical prowess. If it was just about algorithms and data I'd be cheering them on, but it's not, it's mostly about stupid fuzzy human being stuff, and Google has always struggled with that. (Though they're learning quickly!)
If I was going to make a prediction I think Glass will flop. The only way I could see it not flopping is if they get something out there quickly that genuinely looks cool and doesn't have a huge pricetag. (Not because price will inhibit purchasing it, but because if it is high priced it will immediately be known as showing off, ie douchey, to own one.)
I think the next step towards pervasive always-available computing is going to be wristband/watch type stuff with flexible displays which provides a nice step forward ubiquitous-computing wise, leaves room for creative design that can spawn a array of fashions, will be affordable, and will not require forging of new social norms on the way. (I'm 99% sure this is where Apple is headed.) And lets face it, a slick-designed slap bracelet that you can post to Facebook on is going to be fucking cool, whereas a cyborg-like eye-piece is at the very least going to get mixed reviews.