Possibility Set
A. Inmarsat got it completely right and MH370 came down in South arc.
A1. Controlled ditching left nothing on surface
A2. Debris not yet found
B. Hole in Inmarsat calculations as noted by Duncan Steel and MH370 came down in North arc.
B1. Landed in North arc and concealed. Passengers???
B2. CFIT in mountainous terrain while flying below radar.
A1 looks most probable at present.
If/when raw Inmarsat data becomes available, Duncan Steel's possibility set will be either validated or dismissed.