Only the Indian Ocean (64E) INMARSAT was involved in the last ping(s) and so they have ruled out areas (on the 40 degree circle) that overlap with coverage by POR in the Pacific and AOR-E over the Atlantic to the West.
I'm intrigued by the gap between the northern and southern corridors. The coverage maps clearly show this gap exists due to the overlap with POR. However the area of the gap would be at the very edge of coverage with POR, with the satellite very close to the horizon. It is not inconceivable transmissions in this region would only be picked up by IOR. In particular a ditched aircraft in the water may well have difficulty transmitting to a satellite close to the horizon.
From what I see there is a distinct case to make for joining the northern and southern arcs which would once again raise the possibility of the plane being in the South China Sea area. It may have flown a tortuous route to get back to the area it first started - but thats no more unlikely then it ending up over China.
So are the Malaysian SAR authorities being too quick to cease the search to the East of Malaysia?
NB I would love to see similar 'corridors' for the various pings between 1.30-8.11am. This would help rule in/out various flight paths being speculated.