ASP.NET MVC 4 Developer Preview features

Enhancements to Default Project Templates - The Web Site created using Default Project Template gives more modern look.

Mobile Project Template - This is the most important feature in this release. This helps you to create site specifically for mobile and tablet browsers. This is based on JQuery Mobile - open source for touch optimized UI JQuery Mobile Documenation.

MVC 4 Mobile Features

Display Modes - This feature allows the application to select views depending on the browser i.e. Desktop Browser or Mobile. It supports views like _Layout.chtml for Desktop browser, _Layout.mobile.chtml for mobile browser.

Task support for Async Controller - Async Controller returns an Task. The async Controller actions also support timeout.

Azure SDK - Supports for Windows Azure SDK (Sept 2011 1.5)

Looking forward for next release...