As many others, I am thoroughly perplexed by this whole incident. Some of the questions is my mind are:
1. If this was a case of pilot suicide (which I personally highly doubt) why would he have gone through the bother of shutting comms systems down and taken another course instead of simply ditching the plane as soon as possible?
2. If this was a case of a hijacking this would also be highly unusual in that hijackers usually want to make some sort of statement and have their demands met.
3. If this was a case of mechanical failure then why did the aircraft 'ping' a satellite(s) hours later?
4. If this was a case of cabin depressurization, and resulting hypoxia, then the aircraft would not have been able to be turned around to another flight path?
5. Why would anyone fly the aircraft to 45,000'? What purpose would this serve other than "ridding" the aircraft of coherent, or semi-coherent, passengers?
I'm sure there are several other questions I'm not asking.
However, having said all that and this is just my own feelings on this issue: I wonder if the aircraft and passengers landed somewhere else and was refueled to await "further orders"?? I know this scenario is a bit "out there" but......