I recently upgraded from Visual Studio 2010 to the Visual Studio 2012 RC. The installer also installs IIS 8 Express which Visual Studio now uses as the default web server.>
Update your web.config
http://odetocode.com/blogs/scott/archive/2012/08/07/configuration-tips-for-asp-net-mvc-4-on-a-windows.aspx
Removes the need to modify your host configs.