"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
'iPad Mini' Cases Consistent with Rumored Design Details
Some case manufacturers seem to be taking similar dimensions into account with new case designs intended for the 7.85" iPad. As shown here, the side-bezels are much narrower than the top and bottom. The case designs also show off the Facetime Camera and a hole for the rear camera.
The iPad depicted within the case shows the new smaller dock connector, but those device images tend to be rendered mockups based on circulating expectations. In the past, the case designs themselves have been sourced from leaked/stolen specifications of the upcoming Apple device.
Other images show the usual microphone opening at the top of the device, though there is also an extra upper-back opening, the purpose of which isn't clear.