I fly a lot and it is so refreshing to be able to travel without hearing people having conversations on their mobile (and its a nice escape from the phone for a few hours).
I just had a 10 hour flight from Mexico and it would have been so annoying if I had mobile phones constantly going off around me and endless, pointless chatter (especially as it was an overnight flight) ...people tend to speak louder when they are on the phone too.
So if this did happen, I hope as you say, that they create the necessary conditions inside the planes to not disturb other passengers.
Regards, Paul
http://www.paulscottondesign.com