The wording of Defender is now as follows, "Attach Defender to 1 of your Pokémon. Discard this card at the end of your opponent's next turn. Any damage done to the Pokémon Defender is attached to by attacks is reduced by 20 (after applying Weakness and Resistance)." Defender now protects against all attacks, even ones not made by the opponent.
Source: TPCi Announcement (2011-04-11), PUI Rules Team (2011-05-05)