"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
AirPods and AirPower: Everything We Know
Apple to Offer Live Video Stream of Today's Media Event
Apple should also be making the stream available through its website, but the announcement and page for the stream have yet to go live.
Apple's keynote kicks off at 10:00 AM Pacific Time, and MacRumors will have full coverage of the event.
Update: Apple's website has now been updated with the live stream, and the company's online store has gone down as usual ahead of the event.
As with previous events, the stream through Apple's website requires a minimum of Safari 4 on OS X 10.6 or Safari on iOS 4.2.
(Apple TV images via @basvanderploeg)