The Civs and leaders are the "main course" of info giving Firaxis the highest awareness in the communities. Therefore they have a big incentive to stretch these information... I would be more than surprised if not all the 18 Civs, leaders and agendas are defined and even already ready for kickoff from the art-department... I agree that a lot of information is given for us fanatics but we use sources the regular, "casual" civ player wouldn't... (twitch, livestreams, walkthroughs...) You should read some of the commentaries below the youtube-videos and articles and you see a lot of regular customers and even now they are going: "What? Unstacking cities? " "Is this a game for PC?" "Please let America be a civ again" "Civ 5 was so cool - I played it for a few weeks - Will definitely try this out..."