It'll be interesting watching how the Android community deals with this, as they poured scorn on the fragile iPhone 4/4S glass back (note, happy, clumsy, ex-iPhone 4 owner, didn't break for me). They're right though, I'm surprised they didn't learn from the example of Apple and how many people did break their back glass.

Although glass cracking from a temperature shift is pretty odd, I would have thought it'd have gone through testing to isolate faults like that.