I am choosing to keep my screen unprotected. I intend to get a case for it in a couple days, but I have seen numerous tests where the screen remains perfectly fine even after a wild boxcutter visciously attacked it. I'm always usually rough on whatever electronic I get, and my Hero has still failed to get any damage to the screen.
I also really, really like the smoothness of the Hero's glass screen. Granted, it would probably feel similiar with a protector or at least similiar, but eh. And from what I've seen, screen damage to the Hero is not a problem for most people, and if it is, it's because the glass exploded from a drop from the heavens.