The iOS 8 SDK brings over 4,000 new APIs for developers, the biggest release since the origination of the App Store.
Notably, the Xcode 6 beta also features new resizable iPhone and iPad simulators. It's been rumored for quite some time that Apple will release a 4.7-inch and 5.5-inch iPhone. It's also been said that Apple is working on a 12.9-inch iPad. A resizable simulator would be just the type of tool developers need to test their apps against various screen sizes.
There's still tons of new things to discover in iOS 8, OS X 10.10, and Xcode. Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.