According to iMore, Apple is readying a new dock connector for their iOS devices that will be more compact. A downsized dock connector would allow for more space for key internal components.
iMore thinks that Apple will aim to meet the same proportions as a Micro USB port, though doubts Apple will adopt the actual port since “it’s not faster and not Apple’s style.” The current 30 pin dock connector checks in at 2 cm wide, while the entire plug adds up to 2.5 cm.
Apple merely shortened the dock connector by about a centimeter with its last change, which made it slightly more compact than its predecessor.
While some rumors have suggested that Apple is planning to redesign the dock connector of the upcoming iPad 3, not many reports have backed this.