The new, revised crash position is related to new calculations that revised the amount of fuel burnt during the manouevres around Malaysia, to an increased amount - thus leaving less fuel for the flight path heading South.
I think the 400kt speed path is being searched because it corresponds with the new Japanese satellite pics that are being touted as the most credible, because these pics show coloured wreckage that definitely resembles MAS colours.
The CSIRO "simulated drift" graphic shows debris travelling on more of a Northerly path and circulating in the area, rather than being driven rapidly onto the W.A. coast, as I expected it would be.
https://www.youtube.com/watch?featur...&v=oVVWrKn9Gg8