Something very basic changed a but in ActionScript 3.0 – adding interactivity to buttons. This is a nice, short Adobe Video that shows how it’s done now:
http://www.adobe.com/designcenter/video_workshop/?id=vid0130
(duplicate link from a previous post, recontextualized here)
This other video showcases the same type of interactivity, but using Script Assist (which slows down the programming process, in my opinion). Still, it’s useful for showing how the Class structure is now organized:
http://www.adobe.com/designcenter/video_workshop/?id=vid0131