Mildly surprised it wasn't Planescape or Spelljammer, although I now suspect that those two setting will be covered by published Adventure Paths (sort of like how Storm King's Thunder acted as a quasi-Campaign Setting for the Savage Frontier, and Tomb of Annihilation acted similarly for Chult) . . . Perhaps by using Dungeon of the Mad Mage as a springboard.
Mildly disappointed it wasn't Dark Sun, even though I was certain it wouldn't be. Fortunately, it's fairly easy to whip up a homebrew Dark Sun-inspired setting in 5e, even if you have to leave out the psionics.
Excited that it turned out to be Eberron. Much prefer Eberron to the Forgotten Realms.
Bring on the necromancer elves, druidic orcs, dinosaur riding halflings, and robot Warforged!