You've never really been entitled to privacy in a public space, this is just kind of driving home that point. When you're in public, you are in fact, in public. I care about my privacy to the extent that I don't want to be harassed or identity-thieved, but this fear over people being recorded walking around the city park is conservative and ridiculous. Any NON-public space, however, is another matter, and there are actual laws for that, which will probably need to be updated a bit more as technology progresses.
Agraza sort of mentioned this already, but the vast, vast, vast majority of privacy loss is self-inflicted by people. If you don't want your private business to be public, that's is perfectly achievable, you just have to not use facebook/twitter/google. If you want to conduct private business in public, you have always run the risk of it not staying private. There's also a significant difference between your personal phone calls being record & transcribed and, again, being recorded in a PUBLIC place.
I do have things I wish to keep private, and you know what? They have stayed private, because I ensure that I don't involve a public venue or service. If you're concerned about people recording you reading you iPad at an outdoor cafe while sipping your coffee, you have way too little to worry about in your life.