Kick Me!: Whenever Bombastic Bag-Man takes damage from an attack, deal the attacker penetrating damage equal to the damage taken by Bombastic Bag-Man. Bombastic Bag-Man can’t be healed except by the Fantastic Four team ability.

If Bombastic Bag-Man is on his last click and is dealt 4 damage, how much damage will Kick Me! deal to the attacker? 1 or 4 penetrating damage?
One penetrating damage. The damage taken is consider the number of clicks applied to the dial. In this particular example, only 1 click is applied before the Bag-Man is KO'd, so the attack is only on the hook for 1 damage.

And, yes, if you've been playing Heroclix for more than a little while, this is a new ruling (as of the 5-15-11 PG).

Updated to reflect changes in latest PG (5-15-11).