"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Apple Releases watchOS 2.1 With Improved Language Support, Bug Fixes
The 2.1 update can be downloaded through the dedicated Apple Watch app on the iPhone 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.
watchOS 2.1 includes a range of bug fixes to improve the performance of the device and it also includes support for several new languages. There's now system language support for Arabic, Czech, Greek, Hebrew, Hungarian, Malay, Portuguese, and Vietnamese, along with expanded dictation and Siri support for several languages. Bug fixes address issues in Calendar, Power Reserve mode, third-party apps, and more.