With the advent of TxP, we get the first two anti-Speed cards that actually work and aren't useless against non-speed: Mayhem and DD. I think there should be more.
Nebuchadnezzar's Court
Green Site
"When a Lost Soul is Rescued from this Site, all players Discard all cards in hand except 10."
The Rich Young Ruler
3/3 Multicolor Evil Enhancement, TC
"Place on your N.T. Human Evil Character. Any time your opponent's hand exceeds 13 cards, you may Discard this card to view opponent's hand and Discard a card."
Masada
Fortress
-Holds any number of N.T. Heroes-
"You may Discard a Hero from this Fortress to Negate a Good Enhancement in play or set-aside that was played when no Evil Character was in the field of battle."