Safety Briefing
All these discussions made about safety briefings will never dispel the fact that only a small minority of pax will be conscientious enough to take the information in! For a variety of reasons many are to busy getting settled between pushback to taxi and takeoff to take anything in.'There is going to be no emergency anyway' will always be in the back of most passengers mind's.
If anything catastrophic is going to happen it will be always very quick with no time to do anything , with the majority of inflight problems usually very minor these days if there is a problem requiring passenger survival notification in the form of a briefing then the captive audience I am sure would be very attentive!! In the meantime the requirements to brief will always be there!