“The report also mentions an observation of an unknown connection on a cable carrying the device’s volume buttons, mute/vibrate switch, and power button, speculating that it could be related to NFC capabilities.”
“On the iPhone 4S, the volume buttons and mute/vibrate switch are located on the same component as the headphone jack and noise canceling microphone, but with the headphone jack moving to the bottom of the device in the next-generation iPhone, Apple has tweaked the component grouping on its flex cable parts.”
If you are just noticing now, the rear shell looks like it no longer will be just glass. Many believe the back is some sort of aluminum casing. Personally I’m not used to seeing a two toned back just yet. Have you warmed up to it?