The Civilopedia is actually one of my favorite features in these games. So I think we should have a thread about it. I tend to like these kinds of encylopedic efforts in history-based video games, even if they aren't necessarily the most reliable sources of information.
First thing I should ask is: Is there a way to have the Civilopedia be accessible from the main starting menu (where you can set up new games, etc.)? I know you could access it in Civ 4 from the main menu, which I thought was a lot more convenient.
My second comment is that the Chinese civilization page is a little bit short in my opinion. Japan's entry is much longer, which seems arbitrary to me. I know they were trying to condense China, but I think they did a little bit too much condensing. I think there should have been at least some information (a few sentences at least) on all the major dynasties. Let's assume that "major" means Shang, Zhou, Qin, Han, Tang, Song, Ming, Qing. Yuan is excluded because they can be covered in the Mongol page. I find it odd that the civilopedia page would bother to give more information about the Xia, a pseudo-mythical dynasty, than any of the really important ones. I think maybe a little bit more information about the Warring States could be added too, such as the fact that aside from being an "agonizing" period for China, as the civilopedia page puts it, this period also gave birth to the so-called "Hundred Schools of Philosophy," including Confucianism, Daoism and Legalism. They could probably add something about modern China (particularly Mao Zedong and Deng Xiaoping) as well.
Second. Few errors I've noticed:
Askia's title is listed as "Ursuper" instead of "Usurper." We all know Askia was super, but that's not the significance of that title.
From Nobunaga's Civilopedia entry: "His two lieutenants, Toyotomi Hideyoshi and Tokugawa Ieyasu, would complete the job, reunifying Japan blah blah blah" My gripe here is that I think it's erroneous to call Tokugawa Ieyasu "Nobunaga's lieutenant." The statement can apply pretty well for Hideyoshi but not for Ieyasu, who was an allied factional leader rather than a simple subordinate.
From Alex's entry: "Alexander the Macedonian is unquestionably one of the great warlords of all time." This should say "greatest warlords of all time."
From Ramesses II's entry: "He is regarded by later Egyptians as the greatest pharaoh in history, a conclusion it is difficult to dispute." I think this should read, "He is regarded by later Egyptians as the greatest pharaoh in history, a conclusion that is difficult to dispute."