This is based on the BBC
Horizon documentary which aired tonight over here, in fact I've just watched it on TV, it was just on two hours ago.
The new position seems to be based on computer-modeling and a lot of number-crunching of data by Inmarsat, based on their satellite which was the one receiving these so-called 'handshakes' or 'ping' signals. I can't say whether their conclusions are more reliable or not, but the documentary clearly inferred that they were.
One thing I DID newly learn was the real source of these 'air corridors' I heard so much about - the 24-hour news channels did a piss poor job explaining them - simply stating that the plane MUST have gone in a north or south corridor arc. Last time I checked, there isn't an invisible barrier in the sky forcing planes into only two exact directions. 
In fact, these routes poorly-described in the news as 'air corridors' are in fact the outer edges of a circle with a set radius of thousands of miles, and centred on the Inmarsat satellite in orbit above the central Indian Ocean. The final satellite data 'pings' from flight MH370 showed only its distance from the satellite, but not its location. The arcs are therefore just the parts of the circle that the plane could have reached on its available fuel. I never actually knew all this before watching the programme.
I'm sure the programme will appear on YouTube eventually palbert if you wanted to watch it.