The document summarizes new features in ASP.NET MVC 4 Developer Preview including enhanced default project templates, display modes for mobile views, jQuery Mobile and browser overriding support, recipes for code generation in Visual Studio, and task support for asynchronous controllers. It outlines requirements, installation considerations, and breaking changes. Key new features are enhanced templates, display modes for adaptive rendering, jQuery Mobile integration, a mobile project template, code generation recipes, and asynchronous controller support using tasks.