Richard,
Under similar assumptions does that rule out the Northern route? I assume that must require a weird combination of speed and track changes to remain consistent with the timings.
Neither the distance change away from the satellite between the hourly pings nor any potential Doppler information would by itself rule out a Northern location, any better than reasonable assumptions about the aircraft being spotted enroute ruled it out a week ago.
It's also not really clear why today's news, if the better Inmarsat analysis is all there's been, merits the appearance of the Malaysian PM or the move of the victims' families to Perth.