ASP.NET MVC 4 new features:
1: ASP.NET Web API:
As what we mentioned in the last year: the old WCF Web API changed name to ASP.NET Web API, and then moved in ASP.NET MVC 4.
ASP.NET Web API, a new framework for creating HTTP services that can reach a broad range of clients including browsers and mobile devices. ASP.NET Web API is also an ideal platform for building RESTful services.
We had to install ASP.NET MVC 4 package before but now if you have Visual Studio 2012, the MVC 4 has already been included in.
2: Enhanced Project Templates:
We can see better project templates when we try to create a MVC 4 application, such as Mobile template, Web API template and regular web applications;
3: More improvement for Mobile feature such as jQuery Mobile;
4: Display Modes:
The new Display Modes feature lets an application select views depending on the browser that's making the request. For example, if a desktop browser requests the Home page, the application might use the Views\Home\Index.cshtml template. If a mobile browser requests the Home page, the application might return the Views\Home\Index.mobile.cshtml template.
5: Asynchronous methods control enhanced;
6: Controller can be added to any project folder, which is more flexibility to organize code;
About more details, please read Microsoft official ASP.NET website.