Lithium Batteries Theory
MH370 theory (based on my own opinion about breaking news regarding lithium batteries onboard the jet's cargo area)....
Freescale employees (~20 onboard) were carrying cargo with them that included Lithium batteries for demo purposes (see previous fires caused by such batteries including a UPS 777).
Upon learning of the fire, the jet changed course back towards Malaysia, explaining why the pilots flew towards the northern tip of Malaysia (closest land) instead of back to Kuala Lampur.
The fire resulted in a gradual loss of pressure which caused Hypoxia but did not bring down the aircraft, and simultaneously slowly melted the communication devices (explaining why one was shut down and then another 14 minutes later), but did not affect the engines (explaining why the engines continued to "ping" satellites for hours). The jet kept cruising westward as the pilots were unconscious until it eventually crashed into the Indian Ocean.
You heard it here first.