[Molecula]

Ну, если по Вашему то так:

var k:Number = 0.1;
var mouseListener:Object = new Object();
mouseListener.onMouseMove = function() {
    test._x = test._x+(_xmouse-test._x)/k;
    test._y = test._y+(_ymouse-test._y)/k;
    updateAfterEvent();
};
Mouse.addListener(mouseListener);