Nothing grants a blanket penalty to saving throws anymore, to the best of my knowledge, as that would be quite powerful. However, there are many options to get conditional penalties on saving throws. Below is a list I came up with.
Fate Rolls On (Divine Power)
Power of the Sea (Divine Power)
Trickster's Fortune (Divine Power)
Diminishing Spirit Curse (Dragon 381)
Genasi Fire Affinity (Dragon 367)
Tenacity for Living (Dragon 385)
Punishing Spike (Player's Handbook 3)
Dominating Mind (Player's Handbook 3)
Thunder Hammer (Martial Power)
Orb of Imposition (Player's Handbook)