It is quite obviously a fake website, ie a viral campaign initiated by Take 2 Games (confirmed in the dns records for civanon.org) but to be honest, it’s a bit of fun so who cares.. it’s not like they have tried to hide themselves which only makes the company look a fool when people do find out its fake..
It has some hilarious stuff in general on people who “play” civilisation and more importantly some screenshots that are not on the main website. The video is the best bit so make sure you catch that. It’s a shame that the video is in Quicktime format – have they not heard of Flash video???
Btw – you can see the official civilization 4 (aka civ 4!) website here.
[update] the site now has take 2 at the bottom of the site so guess they decided to “come clean”..