A little while ago AutoCAD 2013 was released in Japan and now it is the US release. Before we were only able to reveal some of the details.Now here is the full list of What's New for AutoCAD 2013.
User Interaction
- Welcome Screen

A Welcome Screen is automatically displayed when you launch AutoCAD 2013. It provides easy access to drawings, learning tools and online content.
In the Work panel of the Welcome Screen, you can create new drawings as well as open your existing drawings and sample files. A Recent Files list provides easy access to your most recently used drawings.
The Learn panel offers an overview of functionality new to AutoCAD 2013, provides links to videos to help you get started in AutoCAD 2013, and it includes additional learning resources.
In the Extend panel, you can easily download apps from the Autodesk Exchange and connect to Autodesk 360 and social media resources including Facebook and Twitter.
You can choose not to display the Welcome screen during startup using a control in the lower left corner. It will still be accessible from the Help menu.