Windows Vista is fantastic so far (it's only been about 2 ½ days). I can say it's the little things that make it so great, like having WPF tie in the new Aero effects into applications.
Notice that in Visual Studio for instance the code editor control hierarchies display previews of the control you are referring to:
The Document Outline pane also supports this feature.
Notice three different representations (2 buttons, a tree node view of the type and name of the variable, and the XAML) of the same information on screen.
All 4 items in the GUI arel synchronized and selected at the same time:
This is brilliant. I wonder if the Button objects are the same object really, and how the resources are managed. Tooltips will get a lot nicer going forward.
I'd like to see an additional feature added to this that allows you to click on it to center the control in the design window.
This feature works in other areas in the IDE as well ... still experimenting.