CNN is now saying it may have flown for an additional 4 hours...into the Indian Ocean.

This tells me either the crew was incapacitated, or it was hijacked, or one of the pilots took it for a joy ride.

I still think that they had some type of electrical short in the E/E bay and turned back to return to Malaysia. Then they descended due to smoke in the **** and/or cabin, then the crew was incapacitated and the airplane flew on autopilot at what ever altitude they had set (10,000' is what we usually use for a decompression/smoke event) until it ran out of gas (4 more hours?) and then the engines flamed out and it went into the Indian Ocean.

It that's where it is, they will have a very hard time finding it. Needle in a much bigger hay stack...and a week late to the party.