The MMA/UFC issue comes up every couple years. I believe UFC at least has catered to the concerns of watchdogs by lessening the high-impact nature of it all. But seriously, what is so different with this stuff from boxing? I've personally seen at least 1 fighter get killed in the ring on television. Legally too. No fouls or anything.
Its way safer than boxing because the fighters take less head shots and the fights are stopped earlier. The attitude is that its better to be safe and fight another day than to risk serious head injury.
I think its great for the sport, the athletes, and everyone.