The iPhone 4S appears to be made out of the same garbage fragile glass that shatters from simple drops. The iPhone 5 would, hopefully address the problem by using a more practical material (aluminum or some other metal) on the back that can take a drop. The iPhone 5 also would, hopefully, have had some protection for the glass edge on the front of the phone to prevent the glass pane from taking a direct edge hit and causing shattering.
Using glass to make a phone was among the dumbest ideas Apple has ever had. The material is too fragile for everyday use and is incredibly slippery in the hands, leading to drops and shatters.
If I'm paying $299 for a phone, it needs to be durable enough to survive a 2 year contract. Glass is not a durable material. And please, spare me the "if you take care of it properly" -- that's nonsense. You could have a phone made of a tissue paper that survived a contract if you "took care of it correctly" -- accidents happen, especially on a device you use for business every day that is going in and out of your pocket.