More Intelligent Charging
Although the Qi wireless charging standard already includes the necessary smarts to guarantee safe and reliable charging, Apple could take this up a notch in its typical style, by virtue of controlling both ends of the solution.
This could include features that monitor battery health and adjust the charging current appropriately so as to help prolong battery life, as well as being able to exchange signals for optimal temperature so that the charging mat ramps down its current if it detects the iPhone heating up to levels that are not ideal for the battery.