"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Issues Invitations for iPad 3 Media Event on March 7
Image from The Verge
Apple is of course expected to introduce the iPad 3 at the event, with an upgraded Apple TV set-top box also reportedly in the plans. Rumors have also suggested that Apple could show off a new high-definition audio format with "adaptive streaming" that could allow Apple's iCloud and iTunes Match services to send varying qualities of audio files to different devices depending on bandwidth and hardware requirements.