"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
iPhone 6 Plus Reportedly Accounting for 60% of Total iPhone 6 Device Shipments
Foxconn is said to be responsible for the production of the iPhone 6 Plus, while Pegatron is in charge of the iPhone 6. While parts shipments to both suppliers were even as the launch of both devices neared, Foxconn appears to have received more parts shipments for the iPhone 6 Plus as of late.
Apple announced last month that it opening weekend sales of the iPhone 6 and iPhone 6 Plus topped ten million units, although the company did not specify how that number was divided between both units. Shipping estimates for new iPhone 6 orders remain at 7-10 business days, while the iPhone 6 Plus is still showing a shipping delay of 3-4 weeks.