If you've read Noah's impressions, watched his videos, and the like, you'll realize that the HTC HD2 is quite the popular device. That being said, it's not invincible, so when it tried to pick a fight with the concrete, the concrete had the upper hand. Turns out that the device's 4.3-inch touchscreen and small bezel played a role in the screen shattering. Ouch.
The moral of the story - if you get your hands on an HD2, be very very careful.