"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
'IP Application Development' Files for U.S. iPad Trademark
The company has been loosely connected to an Apple shell corporation called Slate Computing through a similar iPad trademark application in Canada. The U.S. trademark application arrives in the backdrop of Apple interest in contesting Fujitsu's U.S. iPad trademark.
We believe it's likely that Apple is behind the IP Application Development company's actions, though no further evidence links the two companies. Apple is rumored to be introducing their tablet next week at a media event on January 27th.