I agree, I miss the line brawls and goalie fights too. Whenever there is a brawl on the ice with three different fights you hear about it nowadays.
I'll say this though, I don't think fan fights have changed a whole lot. People still drink like fishes and lose their temper. You can see a whole slew of modern fights on Youtube in games. Still lots in NFL games, which are the craziest of all the 4 sports.
I can remember specifically January 20th, 2007. Leafs at the Pens. The Pens won 8-2 with Malkin collecting 5 assists. The third period, when the game was out of hand, was a fight fest. McCabe vs. Thorburn, Gill vs. Thorburn, Green vs. Talbot. Lots of fighting. For whatever reason the fans fought a lot in that 3rd period too. I had a perfect view behind the net on the upper bowl at the Igloo. During the game, during a stoppage, whatever, there was someone in a Leafs jersey slugging it out with someone else. We honestly watched the stands more than we did the ice in the 3rd period. It was a hostile game, but boy was that not as fun of an experience as I've ever had at a game.
So yeah, as long as there is alcohol in the world there will be fan fights. I don't think that will ever go away, there are always drunk idiots.