They've been doing everything possible to maximize player safety in the NFL the past ten years or so. it's a sad reality that not enough was done before, and possibly there is nothing that can be done for those who have long careers. What Baron said is correct, first of all you can't completely avoid head contact with how fast the game is. And then there is the fact that a hard (and clean) hit to the midsection will often lead to players banging their heads on the ground. I would think most or all of the deceased players from this study played all or most of their careers before there was a bigger emphasis on player safety and head injuries.
I think the major implications are that less and less kids are going to play football. There will still be plenty that do though, more than enough to fill college and NFL rosters. So does this do anything to NFL and College football viewership? I'm not sure. Seeing reports like this are sickening and make me feel a little bad for complaining that the NFL has become too pussified.