The Cleric of Fate Domain and the Cartomancy Feat (which was our first hint of the new Class Groups) from the UA seems likely, as are the Feats and Spells. Hard to tell what was what, since they mixed Giant, Planescape and Deck of Many Things material in n one drop.
With the benefit of hindsight, it's not to difficult to figure out what goes with each book.
Glitchling - Planescape
Fate Domain Cleric - Deck
Runecrafter Wizard - Giant
Primeval Druid - Giant
gate warden - Planescape
giant foundling - Giant
planar philosopher - Planescape
rune carver - Giant
Rune Carver Apprentice - Giant
Scion of Elemental Air - Planescape
Scion of Elemental Earth - Planescape
Scion of Elemental Fire - Planescape
Scion of Elemental Water - Planescape
Scion of the Outer Planes - Planescape
Strike of the Giants - Giant
Agent of Order - Planescape
Baleful Scion - Planescape
Cartomancer - Deck
Cohort of Chaos - Planescape
Ember of the Fire Giant - Giant
Fury of the Frost Giant - Giant
Guile of the Cloud Giant - Giant
Keenness of the Stone Giant - Giant
Outlands Envoy - Planescape
Planar Wanderer - Planescape
Righteous Heritor - Planescape
Rune Carver Adept - Giant
Soul of the Storm Giant - Giant
Vigor of the Hill Giant - Giant
Spells - all from Deck. I think it's the only one that will feature new spells.