What I take from this is that the NFL has got it exactly right. Don't lead with the head, don't target the head. If you come in with your shoulder and keep it low the chance of concussion is greatly reduced. If McLeod had him in the head/neck area I have no doubt it would have been a bad concussion and potentially ended Sanders' career.
Great play and just what the NFL wants. Aggressive but less dangerous play. It can still be a violent game without being a head-hunting game. Everyone should learn from that hit. That's how the NFL can still be a hitting game without seriously endangering these guys who are putting their bodies on the line for our entertainment (and a bit of $$).
Tom