Without the transponder on I can see how it could be lost. Not so sure anyone is looking better at this point, but I see what you are saying.
You think China could be ripe for a terrorist attack from this mystery? Wouldn't that be something........awful.
It would be terrible. LOTS of possibility for loss of life, though--a big 'show'. I certainly hope it's just my brain spinning tales (too much reading/research into terrorism--damn Pol. Sci. degree HAHA).
It's just possible that the entire cockpit went whackadoo and the pilot had to make an emergency landing somewhere remote (although it would be hard to find an island with a long enough landing zone for a 777 that isn't occupied). Maybe where cell phones don't work? I think I want to believe that. *makes my mind up to think positive*