They're just "super goody huts" by the sounds of it.
Fortunately, they've realized this is a feature many people like to turn off, so we can (in Civ4; I am not going to consider Revolutions a real Civ game). If only they had toggles for everything ("No Corporations", "No Espionage", "No Wonders", etc). Not that I dislike them, but I'd like to shake up the game more now and again.)