"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Siri for Mac’s Colorful Waveform Dock Icon Revealed Ahead of OS X 10.12 Unveiling
In the menu bar, there's a simple Siri black and white icon that features the word "Siri" surrounded by a box, while the full dock icon is more colorful and features a colorful Siri waveform in the style of other built-in app icons. Clicking on either of the icons brings up a Siri waveform to give users a visual cue that the virtual assistant is listening for commands, much like on iOS devices when the Home button is held down.
In addition to accessing Siri through these two buttons, a hands-free "Hey Siri" activation command is also supported. "Hey Siri" is an option that's disabled by default at the current time, but it can be turned on in the Preferences menu.
Siri integration in the Mac is still in the early stages of development, but the assistant will presumably be able to answer many of the same queries and perform many of the same tasks it can on iOS devices - opening apps, conducting web searches, controlling HomeKit, sending text messages, reading emails, setting calendar events, and more.
Because work on Siri is far from complete, there's a chance these icons could be tweaked between now and when the feature is introduced as part of OS X 10.12 at Apple's Worldwide Developers Conference. The Menu Bar icon in particular looks like it could be a placeholder icon, with a finalized design, perhaps depicting a microphone or waveform, to come in the future. Apple has also been known to shelve expected features at the last minute if work is not complete and up to the company's standards.
WWDC is set to take place from June 13 to June 17, with a keynote event scheduled for Monday, June 13, which is where we'll see our first glimpse of OS X 10.12 and iOS 10.