This latest development both confirms my suspicions, and raises some potentially disturbing theories.
At this point, a hijacking seems to be the most likely plausible reason for the plane's disappearance. This would both explain the lack of debris, and the lack of any communication from anyone aboard. Combined with the news that the plane was flying off-course, it all lines up.
So, the plane was hijacked. But the question remains: Why, and what of the crew and passengers?
As fucking morbid as it is to say, I'm forced to say that I think that everyone aboard the plane is probably already dead. With how long it's been since the plane disappeared, and no one taking credit OR issuing ransom demands, it's clear that the crew and passengers aren't a priority to the ones responsible. And keeping that many people alive for this long without a reason is extraordinarily unlikely.
If it is indeed a hijacking, then it's clear that the one's responsible wanted the plane, not the people. And frankly, the only thing that I can conceive of them using a plane for is, well... a terrorist attack in the form of 9/11.
Only time will tell the truth, but that's what I gather from all this.