Bushfiva
Very nice idea, to use the entertainment system to force people to acknowledge "I understand". However, I have suffered from too many of these mandatory computer-based classes on business ethics and the like to know that after a few, you just click through the "I understand/agree" buttons as fast as you can (or are allowed to) to get it over with. That is, if the safety brief would essentially remain identical, just delivered through the entertainment system instead of live. And what do you do with passengers who refuse to click? Are you going to ground the plane until they do?
What I much rather would like to see, after reading your suggestion, is a "safety" department in the in-flight entertainment system which would provide me with in-depth technical and/or practical information on in-flight safety which goes much deeper than the 2-minute safety brief before take-off. So that I can expand my knowledge on this if the movie doesn't interest me or my book is finished. Perhaps in the form of a dozen or so five-minute videos which expand on the topics that are touched upon in the safety brief.
For example, a five minute topic on blood oxygen, hypoxia, time of useful conciousness at various altitudes, "cabin altitude" vs. "flight altitude", how a plane is pressurized (by the bleed air from the engines), the effect of inhaling 100% oxygen when flying unpressurized at altitude (prevents or delays hypoxia), why you need to pull the mask towards you in case of a loss of cabin pressure (so the valve opens), and what, at the same time, the pilots will do if the pressure is lost (steep dive to get down below 10.000 feet ASAP - that might be very unnerving if you don't know it's going to happen).
If you were to build each of these five-minute videos the same way, by starting, in easy to understand but technically correct terms, how a certain system in an aircraft operates, what happens if the primary system fails and what the backup system is and how that may affect the passengers, I think that a lot of passengers would take the time to watch all of these videos. And as a result be much better prepared for an emergency than the safety brief could ever accomplish.