We have set up a Divinity Wiki at Gamepedia.com, which focuses on Dragon Commander and Original Sin. See:
http://divinity.gamepedia.com/I've been adding Dragon Commander and Original Sin content lately, but any help would be very much welcome! We are looking for both regular contributors and new administrators, if any prominent users from the forum would be willing to join us.
I know there are other Divinity wikis out there, but the Wikia one is currently pretty much dead with none of its administrators around for years, and another that is just a subcategory of a larger general gaming wiki, which I don't thing is a good idea generally.