I forgot where I heard this or seen it, but I think it was Itachi who said there are only 3 people capable of using the Mangekyou Sharingan. Himself, Sasuke, and someone else. Is that Kakashi?
The Sharingan discriptions on naruto fansites say that Kakashi can't obtain it cuz he isn't a true Uchiha, but chapter 276 proves it wrong.
So... Did Kakashi copy it from Itachi during their first encounter, or is there more to it than meets the eye?