I wouldn't use it in public because I wouldn't want to broadcast my conversation to everyone in earshot of me.
How many people do you see walking around talking on speakerphone?
Kind of the same concept
You could wear headphones while FaceTiming. And I see people on speakerphone all the time.
But say you wanted to show someone the beautiful cities of France.. or some kind of snowy mountain side.. or a trip with your kid to the park, you really couldn't do that.
I know you could take videos of it, but it would be better to do it live. There's something holding us back from our options with Facetime, which is a very futuristic concept. From a business perspective, I guess people would do it for conferences.
Educationally, it would be useful for sharing ideas with projects or something like that.
But still, the quality and resolution has to be way up there though, better than HD.