I have a screen protector on it now, but it just annoys me. Though, to be honest, I didn't take the time to make it "perfect" so there are some bubbles under the screen. Still, it's never gonna feel the same as it did without a covering on it.
What I'd love to see is someone do a scratch test on the Hero's screen. Something like this:
http://www.youtube.com/watch?v=eh2g7AIHdc8
If it could handle that kind of abuse, I would probably leave it "naked" like god intended.