I have dropped mine numerous times. Several times onto pavement from various heights. All while it was naked. The only damage it sustained is the corners of the housing have been impacted hard enough to show that the plastic is actually red, with a black coating nearer the surface. Phone works fine. The glass is fine - except during my transition from my iPhone 3G, I once had them both in my pocket face to face at the same time. They were both naked. Yep, the iPhone scratched my EVO's glass. Not making it up - it's so ironic it's funny. The scratch is off the side, in the black, so you don't even notice it. So I don't worry about it.
But to those who say you can't scratch the glass in normal use - you sure as Hell can - my iPhone did to it at least!