It is. I actually played with the last guy who didn't. It was Craig MacTavish. That's how far back I go.
Yes, it is, and it is all the way through. When you go to the local outdoor rinks, I know that, if it's not law, they're certainly asking people to put helmets on, even if it's a free skate, which makes perfect sense to me. I think that's wonderful to do. Even the best skaters fall at times and can injure themselves. Having a helmet on, while it's not the end-all and be-all, does protect.
Now, it's not going to protect so much with concussion, I don't think. Everyone keeps talking about the equipment. I don't believe that's the case at all. I think it's the shoulder, the chest.... In the chest situation, your brain is still shaken within. A helmet is not going to help that. I don't see how equipment is going to make that change.