"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
More Confirmation of 3G iPhone Case Design?
MacNN republishes photos from iDealsChina which claim to be case moldings from Griffin Technology for the upcoming 3G-capable iPhone. Alongside the case images is a rendering of the 3G iPhone shape.
The moldings reveal the same tapered shape that has been circulating in rumors and photos over the past few weeks. Another case manufacturer had previously posted photos of the 3G iPhone case with a very similar design - with a curved back and a larger opening for the earpiece. The larger opening is presumably there to allow for the additional sensor that has been rumored.