In light of this one would have to go with the southern arc with a ditching in the waters off the northeastern coast of Australia rather as opposed to the northern arc where they would likely drop the landing gear to put it down on some out of the way landing strip.
BTW on Fox this morning an aviation expert said the same thing -- he believes it is along the southern arc ditched in the deep waters there off the Australian coast.
My one question about that would be this:
Wouldn't it have to fly through Indonesian airspace and over Indonesia itself to get there and wouldn't Indonesian radar have picked it up and done something???
Of course Indonesia is not talking -- atleast to us.
Southwest ground track takes out over Indian Ocean.