In a word, nothing. It is, without a doubt, one of the best sports to watch in the world. It's fast, it's physical, and there are generally great swings of momentum during the game. The recent events in the NHL of stick work by their players has brought the controversy of violence in the game, once again, to the forefront. In these cases, the league has, in my opinion, made a mistake. The Belak incident was clearly an act of aggression gone awry. I see the replay of the event and it is clear Belak must be held accountable for his actions, although I don't think he meant to hit his opponent in the face with his stick. He was off balance and that is what caused the stick to be higher up than intended. Of course there is no way to know 100% of his intent but this is my opinion of the situation. Mark Messier's "pitch fork" job of his opponent, to me, was far more calculating. Belak reacted to being held up, however inappropriate, whereas Messier looked his opponent straight up and drove the blade of his stick into the player's abdomen - clearly, a malicious attempt to injure. The league sees it differently.

Belak received 6 games plus two playoff games for his actions. Messier received two regular season games. The differences:

1. Belak is NOT a star in the league. He is a gritty player with one goal this season.
2. Messier is a "former" star in the league. He gets special treatment (the benefit of the doubt?).
3. Belak hit his opponent in the heacarelessa carless swing of the stick.
4. Messier struck his opponent in the stomach on purpose.
5. Messier is likely to retire after this year, Belak will play again.

The league seems to feel the hit to the head warrants more punishment than an intentional strike to a player's mid-region. In most cases I would agree. In this case, I do not. Both acts should have gotten the same punishment, 3-5 games. The recent Bertuzzi incident has clearly muddied the waters of the disciplinary committee.
Having said all this, however, there is still a need for the players to regulate themselves and bring the words "sportsmanship" and "respect" back to the ice. Neither the league nor the officials can bring that back.