From a former flight service manager / aviation human factors student and enthusiast:
(operated B733, 734, 738, 762, 763, 743, 744; A320, 332, 333 over the years)
I have been following this thread since inception. Very enlightening - thank you for all your insight, theories and discussion.
Lots of current talk about CVR duration - if some of the speculated theories are correct (decompression / hijack / smoke event et al.) I presume that in this technological age there will be recordings of this on camera-phones (and potentially even "water resistant" cameras) from within the cabin during any period of passenger consciousness.
In my many years of flying it has become apparent that there has been a recent surge of "pocket paparazzi" - everyone is eager to record any unusual events on mobile devices. Recent recordings / photos include evacuations (LOT, US Airways) and even relatively minor turbulence events etc.
In high-impact accidents it is still possible to find casualties intact - possibly with phones in pockets - I am intrigued to see if any media devices are recovered. Collaboratively with FDR / CVR information this may paint a very interesting (or horrifying) picture of the cabin environment prior to impact. Perhaps stored data may yield clues in this eventual investigation, regardless of FDR / CVR recovery or analysis.
I am unsure of current protocols about eventual release of this potential media device information - does it "belong" to the estate of the deceased or can it be released for "public consumption" via official channels? Does anyone have any insight?