Helmets at Ski Resorts

Saw this article in the Times about how helmets are becoming more widespread at ski resorts.  When I was starting to ski in the boy scouts in the mid 1990s, no one even thought to wear a helmet.  Even when I went skiing a few years ago, I don't remember seeing that many people wearing helmets.  Now, I wonder how people think about helmets with skiing, and whether they are going to become more widespread.
At the same time, though, as one person in the article points out, if you're speeding down a ski slope and crash into a tree, the helmet is not going to do much good.