Philippe Leefsma has created a DevTV on the new AutoCAD 2014 API's. You can download this DevTV from here. This DevTV includes Migration of your AutoCAD 2013 plug-ins to AutoCAD 2014 and the new APIs and developer features in AutoCAD 2014. Also,
Visit http://adndevblog.typepad.com/autocad/2013/04/getting-started-with-javascript-api-on-autocad-2014.html for Getting Started with JavaScript API on AutoCAD 2014.