I haven't played The Witcher II, but I know at thing or two about it. The first thing I know about it is that it is good. The second thing I know about it is that it needed more content. I have today learned a third thing about it: the mod tools have been released. Hey, that might mean there's more content available, which makes my second thing invalid, and the third thing has become the second thing, and I know less now than I did at the start of this paragraph. It's making me dumber! Stop stealing knowledge from me, Witcher II!
The REDKit will allow modders to create new lands (including villages), quests, and even new combat rules, while draining me of essential knowledge, and possibly replacing me with some sort of simulacra - pay close attention to my eyes if you ever meet me in the real world, as I'm told you can tell evil clones by their shifty eyes. Sharing is easily done, and there's already a mod up on the site waiting for your attention. A recent patch just dropped into the game, bringing with it a mod manager, so you can keep track of all those lovely non-linear fan quests. It is in beta, so expect bugs, and a whopping 6GB+ multipart download.
Here's a totally inappropriately soundtracked trailer.