What an interesting subject! It is my understanding that the industry has very detailed statistics with regard to this one and to use an old quip if you saw them they'd have to kill you! At one stage I think the % figure of owners who knew how many features their phone had was in the low minority!
I know how many features my mobile has and that's all I need so it's nearly three years old. If people could buy a phone with the features they needed and pay a few pounds every year so that it looked like the latest thing and I was the person reponsible for this simple technology I rather think mobile manufactures, networks and retailers would get together, meet with me and quip...