Redux: How thin is too thin when it comes to smartphones?

Redux: How thin is too thin when it comes to smartphones?: Just shy of a year ago, I asked a question that had been pressing my conscience for a while: When it comes to phones and tablets, how thin is too thin? With slimmer than ever devices on the horizon, it's not hard to question where the line should be drawn, especially with durability the primary concern.
At just 9.3mm thick, the iPhone 4 was regarded as unbelievably thin in respect to its competitors at the time of its launch. But the internal components in smartphones are growing...