I actually like where hockey and football are going with their rules. Intent to injure really isn't fun.
While I will still watch an occasional boxing match I do not watch MMA at all. I've seen several instances where boxers were knocked out and the opponent drops on them and gets a couple more punches in before the ref gets there. I just don't need it.
If football ends it will be because teams can't get insurance. Not the NFL, but PeeWee and High School and even college. That's what will kill football.