Fábio Pedrosa talks about Snoop, "a great utility to explore running WPF applications. It displays the visual tree as well as properties and events. It can be used to map UI elements to the underlying project classes. This application is very similar to the famous Spy++, but for WPF applications. You can inspect the insides of any WPF application, including Microsoft Expression Blend (also a WPF application)."
Another Codeplex project - Source Code Outliner Power Toy - "is a Visual Studio extension that provides a tree view of your source code's types and members and lets you quickly navigate to them inside the editor."
In the June 2007 edition of MSDN magazine there's an article on how MFC has been souped up in Orcas "Most of the enhancements made to MFC focus on UI. When an MFC application is recompiled with Visual Studio "Orcas," it gets an automatic face-lift for Windows Vista—that is, common dialogs will be enhanced, toolbars will follow Windows Vista themes, and window frames and title bars will sport Aero™ transparency. This face-lift happens without modifying any code—all you need to do is recompile the application."