The beta, build number 12F5027d, also includes Xcode 6.3 Beta With Swift 1.2. It is **t clear at this time what the iOS 8.3 Beta introduces, but it likely includes several bug fixes. As a .1 update, it may also introduce new features.
Xcode 6.3, included With the beta, introduces a new version of the Swift language. According to Apple's release **tes, Swift 1.2 includes "a number of **teworthy changes" to the language. Xcode 6.3 also includes enhancements to ease interoperability between Swift and Objective-C code.
New Features in iOS 8.3:
Based on our testing, iOS 8.3 appears to remove the "beta" label from iCloud Photo Library and it offers new CarPlay features, in the form of Wireless connectivity. The CarPlay setting in the image below is located in the General section of the Settings app, below Siri, Spotlight Search, and Handoff & Suggested Apps. Currently, iPhones are only able to connect to CarPlay via the Lightning port.
There's also support for Google two-step verification when logging into and adding Google accounts on iOS, removing some of the need for app specific passwords.
According to the iOS 8.3 release **tes, Apple Pay may be available in China in the near future. iOS 8.3 introduces support for the China UnionPay network as previously rumored.