This contains info regarding the legion artifacts, which some might consider spoilers. Proceed through this post at your own risk.

Having just finished the first round of artifact research on the alpha, I took some screenshots of the story recorded in the Libram of the Dead, that shows the lore behind the artifacts. I won't be able to get further than this for a while though, due to the alpha realms getting shut down, and characters wiped due to legion moving into beta.

The pictures can be found here: http://imgur.com/a/tVI9K