Apparently the iPod 3G is cracking already. Allegedly it is happening spontaneously and not due to droppage, etc. The cracks don’t surpise me so much, especially on the white ones. To get the white a zinc is needed to be added to the plastic and that inherently weakens the plastic. The crack also seems to be appearing around the headphone jack hole, so its likely right on a weld line.
I’ve been thinking about what may have caused this.
If the plastic parts are molded of polycarbonate and the injection molder didn’t dry the resin properly before they processed it then the parts will show signs of being brittle instead of being unbreakable.
Edit: One more thing. Drying resin is usually done as a batch process, so some batches of plastic parts may be perfect and some may start cracking. It depends on the reliability of the process at the molder.
My money is on a China sub-contractor forgetting (or failing) to dry the polycarbonate. Shall we start a pool?