User blog comment:The Rim of the Sky/Bethesda to Publish Physical Lore based books on the Elder Scrolls series/@comment-188.141.67.213-20141022201402/@comment-75.187.252.99-20141024132814

That is a good question! I am only speculating, but i'm thinking probably mid-to-late 2015. Or possibly early 2016 at the very latest.

Not much is known about the setting of Fallout 4 so far. When asked to give hints as to the setting of the next Fallout game, Jason Bergman said (translated from Norwegian), "You'll get no tips from me. But the Mojave Wasteland was a fun place to explore, wasn't it?" - http://fallout.wikia.com/wiki/Fallout_4