I really don't see the point either, if you actually live the lifestyle of one of those people in the vid's, where your entire day is filled with skydiving, fashion shows and, skipping, then you might have things worth recording, to the degree its worth wearing something on your head every waking moment so you don't miss it.
In reality, 99% of your life isn't worth recording, and the 1% that is, you know is coming and you can take your phone out and record anyway.
The search functions are going to be painfully limited with no direct control. Google jellyfish, you get one sentence, it isn't what you wanted to know, you pull your phone out to do a proper search and get the result you want.
You want to record your kids play, you look at that hot mum two rows over, that gets recorded, you get in trouble when your wife wants to watch the play again, holding a phone, record what you want, look where you want.
A head cam ain't new, and is rarely useful except when you actually doing something worthy of getting vid of.
You're going to go skydiving and rather than record on devices already made, like helmets with cams on, you want to jump out of a plain, with glasses that could easily come off that cost £100's? really?
The reality is, if you really are one of those people with a ridiculously exciting life, where you want to record sports, and hot women all day long, good for you, for everyone else.... I see exactly no reason it will improve your life, or help you day to day.
It could be a pretty useful to take on a holiday, because those are the times you often don't know where anything is, or what restaurants are good, but for every day life where you mostly travel to places you've been before, are generally doing something not worth recording and have a need for more detailed use of the internet than voice activation will allow its going to be of very limited use.