Did you watch the video?The Idea is that the soft skin would move a little before it starts to grip the helmet, absorbing part of the energy before the helmet starts to rotate from the initial contact thereby reducing the movement of the head.It is a lot like the new softer walls in Auto Racing. Except in this case the energy energy absorbing material is on the object that is moving rather than the stationary one.The function if a helmet is to absorb energy before it is transferred to the head .If this movable outer layer soaks up part of the impact in addition to everything else that a helmet is supposed to do,I can see how it could be beneficial.The key is that it is movable stretchy if you will,and even a smooth helmet is not smooth after it the ground with any lateral force,If you think so, take a piece of 40 grit sandpaper and press really hard on it and rub it across an old helmet's surface and see how easy it slides,or look at a helmet that fas slid on the pavement during a crash and see if it is still slick.In a helmet this is just another layer of energy absorption.It still looks good on paper to me.whether you see it or not and these people have done a bunch of research.I don't even think it looks good on paper. I don't see how a soft exterior would be better than a hard one. Less friction on the hard surface.
Maybe I am missing something. We'll see what D.O.T. and Snell have to say about it.
Thanks OldHoss that is where I saw it at before.Here is a link I remembered from a post Knifemaker posted in the safety forum on Feb 16, 2009. There is a bigger write-up about the skin on the helmet and how it helps reduce injury to the head.