Nike has offered to give 75 women running in the Oly marathon Trials a pair of Nike luna racers and a uniform. Anyone know much about these shoes? They seem to be extremely light, made from some new material which cuts down on weight significantly. I assume Nike would not send women about to run a marathon shoes that are not meant to handle the 26.2 mile distance, but wondering if anyone has any input on these. They feel great, very responsive.