What you guys are talking about is made by Rudy Project. Carrera (Italian makers of helmets and sunglasses, not the frame makers) also made a model like this that the Cantina Tollo team used to wear in years past. It's not a hard shell helmet, and not made out of the hard foam that you're used to helmets being made out of.
It doesn't pass CSPC (I think that's it...) or SNELL safety tests, and thereby isn't legal for race use in this country.
I'm not sure if Rudy Project sponsors any Euro teams with their helmets anymore (now they're sponsoring Schrodinger Iron and Prime Aliance though who can't use this model since it isn't certified...) which may be why I haven't seen them that recently. These helmets are only about half the weight of 'normal' helmets, and although they don't offer nearly the same protection, it's better than nothing, and apparently good enough for some euro-pro's.
Hope this clears things up.