"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
iPhone 3G S Launch Lines and Disassembly Photos
From Salt Lake City, UT (Thanks Ben)
We're not sure if the iPhone 3G S launch will require long waits in line like previous years. The fact that customers have been able to pre-order the new iPhone will certainly dampen the turnout in the morning. Still that's not stopping some (photo). One analyst predicts Apple will sell about 500,000 units this time around, about one half of the number sold on the launch of the iPhone 3G. Still, that number is twice as much as the sales numbers for the original iPhone's launch weekend.
One French company has already obtained an iPhone 3G S and done a disassembly on the device:
Update: CNet blog documented the opening at the 5th Avenue NYC Store:
First users posting photos: