I'm super excited for Crib Swap in Child of Alara. That's been one of the few effects missing from the deck that I've really wanted. Everflowing Chalice, Abrad, and Conclave Naturalists are all cards I plan on finding places for in various lists. I also think Magnifying Glass will be good for the non-blue grindier decks.
Honorable Mentions include Oubliette, Apprentice Wizard, and the Urza lands for their first time in the new card face at common.
Overall, I think Abrade, Cast Down, Crib Swap, and Everflowing Chalice are going to be strong options for PEDH. What does everybody else think?
CURRENT DECKS
WUBRG Child of Alara, Pauper Dreamcrusher GRBUW | BGU Muldrotha, Dreamcrusher REDUX UGB | WUB Dreamcrusher Pt. III: Nevinyrral's Disco BUW