Like most things, to me, the best solution lies somewhere in the middle.
Emotions are part of every sport, and as long as you don't exagerate in your celebrations, they should be accepted. Hitting a Home-Run is incredibly hard, and you shouldn't be expected to just keep your head down and go about your life like nothing happened. If you score a goal in Hockey, you are allowed to celebrate.
Maybe this was how things were in the old days, but the old days were hardly and example about many other things. Integration is one. I'm not comparing both things, just saying that things change and so does our understanding of them.
Goose Gossage recently went crazy on this subject. I can understand where he came from. To me, as long as you act professional and don't disrespect your opponents, celebrate away.
In Jiu-Jitsu there are rules in place that clearly state that you can neither celebreate too much nor leave the mat until the referee has raised the winner's arm. World Championships were lost because over-celebration. These rules have been a matter of discussion over the years, but I very much agree with them. Be happy all you want, just don't disrespect the sport or your opponent.
In my particular case I don't celebrate too much after victories, but I have punched the floor like a madman after loosing one time - right afterwards, still on the mat, I apologized to the referee and to my opponent (both friends of mine), I was just mad at myself for screwing up. Nobody batted an eye - emotion is a part of every sport.