Has the projected range charts for this flight been calculated at maximum operating heights/speeds? I noticed the press were saying the aircraft could have decended to as low as 5/6000ft to avoid radar but this would have had a drastic effect on fuel consumption surely.
In your absence, 'projected range charts' have been replaced by 'ping arcs' which allegedly show the last received 'pings' returned to the Inmarsat system.
As these were timed at 08.11 the aircraft would have been at the outer limit of it's range anyway however it was being flown, therefore close to if not already at fuel exhaustion.