I'm no expert, but from what I understand helmets today are made to prevent skull fractures and do so pretty well. As mentioned by a few others concussions are from the brain impacting the skull. So my theory is that new helmets will be very similar to current ones externally for skull fractures, but the internal foam will eventually be replaced by a high tech liquid or gel to better slow the momentum of the skull and brain during impacts. Even that won't completely eliminate concussions from the game but I think that'll be the next step. Just my two cents. Also I could see the league requiring full face shields similar to football helmets when they have the visor. I think the league is trending that direction already with the helmet removal penalty during fights and the rookie visor requirements.