I'm just glad to see somebody on this forum finally able to spell lightning. It's sort of embarrassing.
Now maybe ill embarrass myself: an earlier, lengthy post in this thread, about future USB 2.0 and 3.0-compatible lightning cables, confused me. If 3.0 is backward compatible, wouldn't the cables be one and the same? Or are the 2.0 and 3.0 physically different ports? Would someone elaborate? Thanks.
USB 3.0 has nine pins, while USB 2.0 only has four.
Full size USB 3.0 connectors have two rows of pins: the four visible at the edge of the plug, and a second group of five at the back of the plug. The socket is the other way around.
USB 3.0 initially communicates using the USB 2.0 data pins, and negotiates the use of the new pins for superspeed data transfer. If either device does not support USB 3.0 then communication will be limited to USB 2.0 speeds, and the extra pins are unused.
End result is that USB 2.0 peripherals work in a USB 3.0 port, and USB 3.0 peripherals work in a USB 2.0 port (but are limited to USB 2.0 speeds).
(For Micro-USB, the Micro-USB 3.0 connector is wider, with part of the connector compatible with Micro-USB 2.0, and the new pins added in a separate group alongside. A Micro-USB 2.0 plug can fit into the appropriate half of the Micro-USB 3.0 socket, but a Micro-USB 3.0 plug will not fit in a Micro-USB 2.0 socket.)
Existing lightning cables only have the USB 2.0 pins, but if future devices with the lightning port add support for USB 3.0, Apple can start supplying lightning to USB 3.0 cables instead of the existing lighting to USB 2.0 ones.
Lightning to USB 3.0 cables will be compatible with older devices like the iPhone 5. Assuming the iPhone 5 doesn't secretly support USB 3.0, they will behave just like USB 2.0 cables and the extra pins will be ignored.
Future devices will be able to identify whether the cable plugged into the lightning port is USB 2.0 or USB 3.0 (thanks to the chip in the cable), and will adjust their behaviour accordingly.