Exciting changes to Flash Professional in 2013
Flash Pro: Faster, more reliable, and more extensible
“One of the key changes in the next version of Flash Pro is dropping support for AS2. As you may know, we introduced AS3 six and a half years ago, and today it is the most widely used language for the Flash Platform. Given AS2’s dwindling usage and misalignment with the future of the Flash runtime such as AIR mobile app development and Stage3D, we felt it made sense to move forward with AS3 only.
[ Source: Adobe Blogs ]