<p>Any list of Testing frameworks for ActionScript 2.0/3.0 around there?</p>

FlexUnit is the "official" unit testing framework. It's owned by Adobe's Research guys I believe.
http://labs.adobe.com/wiki/index.php/ActionScript_3:resources:apis:libraries
Here's a tutorial on how to use it:
http://langexplr.blogspot.com/2008/10/creating-flex-unit-tests-with-flexunit.html