I haven't seen this mentioned in the thread, but since there are perhaps 100's of posts per hour apologies in advance if this is a repeat:
Given the 8.11AM time-stamp is valid for the last 'ping', this would put the flight in the air some 7.5 hours or so... this would put it about 2 hours past expected landing time - if the passengers were still alive, I'm pretty sure that more than one or two would have become mighty suspicious at least 2 hours previously...
Unfortunately, that fact alone would suggest that (a) they were incapacitated (likely through some cockpit induced hypoxic event earlier in the flight) or (b) there were a significant number of 'accomplices throughout the cabin keeping everyone under control.
I just can't imagine in this post 9-11 world a cabin full of people sitting around good as gold no matter what they were told. If nothing else, surely the cabin crew would also get suspicious?
Thoughts?