As pointed out in the Verdant Sphere thread by Kathranis, it seems that there's a new lore book for 'locks in game called Legacy of the Masters (Part 1), located near the 'lock trainers in Orgrimmar (unknown if there's a book in Stormwind). It's a pretty interesting read, and since not everyone is in the beta (and right now client stability is terrible) I've taken screenshots the whole thing and photoshopped it into one image. A couple of the pages are a bit longer than one book page, so there's a couple duplicates for the top and bottom of those pages.
edit: Arg! Title fail, it should be Masters, not Maters.