One of Microsoft's key marketing points for Surface is reliability--the durability of the device. Here are a couple of Microsoft videos that demonstrate the point.
In the first video, the Surface engineering team talks about development priorities, including durability. Part of the video is a drop test demonstration:
The second video, which shows a Surface with Windows RT being flipped onto a hardward floor from 30 inches, was conducted at the Surface Reliability Lab, in Redmond, Wash., on Oct. 15.