"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Seeds First watchOS 2.2 Beta to Developers
The 2.2 beta can be downloaded through the dedicated Apple Watch app on an iPhone running the iOS 9.3 beta by going to General --> Software update. To install the update, the Apple Watch must have 50 percent battery, it must be placed on the Apple Watch charger, and it must be in range of the iPhone.
It is not yet clear what is included in watchOS 2.2, but it's likely to include bug fixes and performance improvements for issues discovered since the release of watchOS 2.1. It may also include new features to enhance the performance of the Apple Watch.
The first major update to watchOS 2, watchOS 2.1, included a range of bug fixes to address problems with Calendar, Power Reserve mode, third-party apps, and more. It also included support for several new languages.
What's new in watchOS 2.2:
Apple Watch - With watchOS 2.2 and iOS 9.3, the iPhone is able to pair with more than one Apple Watch. Both updates are required, with each watch running watchOS 2.2 and the iPhone running iOS 9.3.