"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Seeds Seventh Beta of macOS Sierra 10.12.4 to Developers and Public Beta Testers
The seventh macOS Sierra 10.12.4 beta is available for download through the Apple Developer Center or the software update mechanism in the Mac App Store for those who have previously installed a beta.
macOS Sierra 10.12.4 brings iOS's Night Shift mode to the Mac for the first time. First introduced on iOS devices with iOS 9.3, Night Shift is designed to gradually shift the display of a device from blue to yellow, cutting down on exposure to blue light. Blue light is said to disrupt the circadian rhythm and is believed to interrupt sleeping patterns.
Night Shift can be activated through the Displays section of System Preferences, where a setting to have it come on at sunset and turn off at sunrise is available. Night Shift can also be toggled on manually through the Notification Center or via Siri.
The 10.12.4 update focuses mainly on Night Shift, but also includes dictation support for Shanghainese, cricket scores for Siri, improved PDFKit APIs, and iCloud Analytics options.
Few outward-facing changes have been discovered in macOS Sierra 10.12.4 outside of the first beta, as Apple has been working on bug fixes and improvements ahead of a public release. With the seventh beta out and the short interval since the last seed, we are getting closer to the end of the beta testing period and are likely to see a public release soon.
Update: The seventh beta is also available for members of Apple's public beta testing program.