Apple today made the second betas of iOS 10.3, tvOS 10.2, Xcode 8.3 and watchOS 3.2 available to developers.
Several bugs in iOS 10.3 beta 1 were fixed. Users were being routed to an "iCloud Analytics" page if they hadn't signed in yet during setup, and iCloud nightly backups were sometimes failing with a "Some files were unavailable during the backup" error. These problems should be resolved, along with some issues with managed and shared devices and Xcode Simulator.
Issues still exist with the new SiriKit car commands, Lightning video adapters, and the Location and Play Sound for AirPods feature.