Along with the release of iOS 11.3, today has also seen the releases of watchOS 4.3, tvOS 11.3 and the first software update for HomePod.
According to MacRumors, the watchOS 4.3 release:
... introduces support for Nightstand mode when the Apple Watch is positioned in a portrait orientation, a feature that was previously only available when the watch was placed in landscape orientation on its side.
Today's update also reintroduces a much-desired feature that allows music playing on the iPhone to be controlled using the Music app on the Apple Watch.
Other new features in watchOS 4.3 include a new charging animation when the Apple Watch is placed on the charger and a new app loading animation when opening up an app. You'll also now see your Activity data on the Siri watch face, and the batter complication more accurately reports battery life.
According to MacRumors, the tvOS 11.3 update
introduces enhancements to Match Content support, automatic frame rate switching on the fourth-generation Apple TV (a feature that was added to Apple TV 4K in a past update), and automatic mode switching for AirPlay video sessions.
MacRumors also reports the release of the first software update for HomePod:
It's not clear what new features are included in the HomePod software just yet, but we are waiting on both AirPlay 2 and a feature to allow two HomePods to be paired together for stereo sound. Apple's release notes don't divulge any details about what might be included, suggesting these features have not been implemented.
According to the release notes, the update "includes general improvements for stability and quality."
We have been unable to test any of today's updates before their public release. So, if you encounter or learn of any accessibility-related changes, regressions or improvements, please do let us know by adding a comment.
How to Update
watchOS 4.3 is available by going to the Watch app on your iPhone and navigating to General> Software Update. To install the update, your Watch must be connected to its charger and have at least 50% battery power.
To install tvOS 11.3, go to the Settings channel then look for the System section near the bottom. From here, look for Software Updates under Maintenance, then select Update Software and Download and Install.
The software update for HomePod should automatically be installed when you update to iOS 11.3. This MacRumors guide tells you how to check the HomePod software version; and how to force an update if necessary.