Introducing, InspectorKit! InspectorKit is both a framework and an Interface Builder plugin. You can check out the source on github. This is basically a major update to the Inspector panel, as it packages all the code into a convenient framework for developers to include in their projects, and allows them to test the inspector at design time.
Smart Crash Reports is an enhancement for the Apple's CrashReporter application. It allows 3rd party developers to register their products in manner so if the eligible application crashes, the crash log is sent to the developer as well as Apple. This greatly enhances the user experience of the OS, and allows developers to receive crashes and improve their software in a timely manner.