[etc]

Нет-нет.

import mx.events.EventDispatcher;
class AnyClass {
    public var addEventListener:Function;
    public var removeEventListener:Function;
    public var dispatchEvent:Function;

    public function AnyClass(otherClass:OtherClass) {
        EventDispatcher.initialize(this);
        this.addEventListener("onAnyClassEvent",otherClass);
        otherClass.addEventListener("onOtherClassEvent",this);

        this.sendMessage();
    }

    private function sendMessage():Void {
        this.dispatchEvent({type:'onAnyClassEvent',data:'test'});
    }

    private function onOtherClassEvent(event:Object):Void {
        trace('Class AnyClass received event from OtherClass data: '+event.data);
    }
}

import mx.events.EventDispatcher;
class OtherClass {
    public var addEventListener:Function;
    public var removeEventListener:Function;
    public var dispatchEvent:Function;

    public function OtherClass() {
        EventDispatcher.initialize(this);
    }

    private function onAnyClassEvent(event:Object):Void {
        trace('Class OtherClass received event from AnyClass data: '+event.data);
        this.dispatchEvent({type:'onOtherClassEvent',data:'hello'});
    }
}

var otherClass:OtherClass = new OtherClass();
var anyClass:AnyClass = new AnyClass(otherClass);