Cupertino has just been awarded a patent for a manufacturing method that can fuse glass structures together while containing all the internal circuitry.
Importantly, the proposed design will be durable (no more cracks, hopefully) and lightweight - as well as being obviously nicer to look at.
In fact, the only downside we can see to an all-glass iPhone is that we might be prone to losing it.
Jonathan Ive is listed as one of the inventors of the technology, and with sapphire glass (probably) tough enough for the challenge, there's a very real chance that Apple might see a promising future in glass.
Via Apple Insider