Given what is known about the missing Malaysia Airliner there is no reason to believe that it was an act of terrorism, it should remain a possibility, but the odds are low at this point. I believe the chance that it was a mechanical error is far more likely. Planes can crash, its not out of the question. I find it fascinating that a plane can still be lost on this planet though. That's the most fascinating part of this story to me.
I think that the crash of Malaysia Airlines Flight 370 was due to mechanical error. I do not think that this was a terrorism thing because there was no target or distress that came from the plane. The plane flew for hours without incident and I think that the radio just went down and they could not communicate.
I think that the crash of Malaysia Airlines Flight 370 was due to terrorism rather than due to mechanical error, because the crash carries too many similarities to the Lockerbie bombing. In that case, the airplane plunged largely in one piece deep into the ocean. Similarly, we cannot find Malaysian Flight 370.
Of course at this point we know nothing for sure and it could be either side. However, it does seem odd about the stolen passport passengers, two of them, and the fact that the connection with land seems to have been manually turned off before the plane went missing. So it may be human intention.