A friend broke his elbow yesterday when a car did a right hook in front of him; he jammed on the brakes but it was raining, and the bike slid out from under him. He also banged his head hard, and was really happy that he was wearing a helmet. It made me think about getting serious about wearing mine again, or perhaps getting one like designer Nathan Will's Torch T1. It has integrated LED lights, red in back and white in front. They are much higher than they would be if mounted on the bike, and almost wrap around, giving a much wider angle of view than conventional lights. There is the added benefit that one is less likely to forget them, or have them stolen.
The helmet features front and rear lenses which the LEDs project onto. This projection method is important as it disperses the light across the lens. This creates increased visibility and brighter light from wider viewing angles. The lenses also protect the LEDs from water, dust, and debris; as you see in the video.
The only downside I see is that one is supposed to replace a helmet after a hit; it is the crushing of the foam inside that absorbs the shock instead of just transferring it to your brain. It doesn't appear to have a lot of venting either, but for city driving in most of the year that is probably not an issue.