I've been thinking that while there are a couple options out there for helmet/light combinations, it seems like there should be more. Specifically, a helmet with a true integrated, high powered light and battery. Not bolted or strapped to the helmet, but truly integrated into the helmet itself. It might not be a mainstream seller, but I could see a dual XM-L setup with a 2-3 hour battery selling well for some of us regular trail riders.

Another option, which some manufacturers like UVEX has done is to make helmets with a bike light mount built in. It's a nice solid mount, but I think something lower profile is preferred. What about a universal bracket with a threaded nut epoxied into the helmet? I'm after something more solid than a rubber band mount, while still being able to adjust the angle of the beam.

Uvex Supersonic:

Others with rubber band mount: