The new JSON visualizer will appear alongside other string visualizers currently available in Visual Studio. These visualizers are accessible through the various places where you can inspect variables, e.g. magnifying glass icon in a DataTip, in a debugger variables window (Autos, Locals, or Watch), or in a QuickWatch dialog box.
Nice! This is going to come in real handy...Related Past Post XRef:
Visual Studio 2013 Update 2 CTP 1 now available [NOTE: This is NOT Go-Live!]