[K.A.T.A.F.A.L.K.E.R]

_root.onMouseMove = function() {
	for(var i in this){
		if(typeof(this[i])=="movieclip")
			if(this[i].hitTest(this._xmouse,this._ymouse,true))
				trace("mouse over "+this[i]);
	}
}

или навесить всем событие onRollOver.