Bethesda has some interesting descriptions of the theme of the game as well. A good chunk of the DLC takes place in a science enclave called "the Big M.T.", and the development team "watched and paid respect to some of the 50s science fiction films from Brain from the Planet Arous, Things to Come!, Forbidden Planet, When Worlds Collide, the Deadly Mantis, Tarantula, the Mole People (although we pushed some of that out for the next DLC), the Monolith Monsters, and more. There’s also a little Wizard of Oz thrown in for good measure… although it’s in the Fallout context."
The DLC is available on Xbox Live Marketplace, PlayStation Network, and various PC digital distributors like Steam.