Well seems that the topic I mentioned here just a little earlier, Brand Attack on the Rise, was took over as a main subject on brand guru Laura Ries’s Blog, in a post on how and when a brand shoul attack.
In general, the leader should never attack or name the competition. Instead the leader should promote the category. By attacking a competitor or responding to an attack ad, the leader only legitimizes the competition and the existence of a choice. Neither is good.