I don't think it has changed anything, but wanted to double check.
From FAQ 3.6:
Consider Penny, who has the text:
Challenges: Kneel Penny to choose a character without attachments. The controller of that character chooses to either kneel that character or choose and discard 1 card from his or her hand.
Can the opponent still choose to discard a card from their hand, even if they have no hand in order to keep their character standing?
I still think it is yes, because the effect of the card is actually just to choose a character without attachments, which was successful. The additional effect allows the opponent to pick one of the options but isn't worded in a way to ensure that choice is successful.
Edited by Slothgodfather, 29 July 2014 - 10:41 AM.