There have only been two apple charging interfaces for iPods, iPhones and iPads (excluding the shuffle), and the new one was necessary (if I understood correctly) to take advantage of faster USB3 data transfer rates.
Lightning doesn't currently support USB3, unfortunately. It did get rid of a lot of obsolete old interfaces that were present in the 30-pin dock connector pinout, though, and opened up possibilities for new devices (like the HDMI adapter).