Some other cool ideas from Eberron:
Major evil groups that pull strings here and there:
* Blood of the Vol - loose ties with Karnath who have a crazy idea about undeath
* Lords of the Dust - a group of ancient Rakshasas trying to bring more chaos and evil back to Khovaire
* Cults of the Dragon Below - crazed worshipers of the darkness trying to bring madness to Khovaire
* The Aurum - a group of rich and powerful trying to line their pockets with even more money and power
* The Boromar Clan - a halfling mafia family based in Sharn. They don't have to bend down to break kneecaps.
The drow don't live underground, but instead hail from the continent of Xendrix.
A prophecy for the world that is guided into being from the dragons of Argonnessen and their agents.
Crystals (shards) that power much of the magic in the world, and the big business in harvesting them.
Sarlona is a continent where psionics are prominent.
If you're going to run the game, I'd suggest getting the Campaign Setting and the Player's Guide. You'll not want to hand over the Setting because there's too many cool secrets that the players aren't ready to see. Instead the Player's Guide gives them an idea of the kinds of characters "resonate" in the setting, and has chapters on each of the important groups, places and things in the setting. You will want to provide your players with copies of chapters 1 - 6 of the Campaign Setting as it has Races, Classes and other development info.
Unless you're going to run some adventures in Sharn, you might want to hold off, because that's a campaign setting in itself almost.
As for the robot slam that people talk about the Warforged, I think of them as the tinsman, who's looking for a heart. Not so much robot-y as they have a disconnect with emotions and their place in the world.