Bethesda will be "announcing new stuff" later in 2013
Bethesda Vice President Peter Hines has confirmed the publisher will announce new games later in 2013, and by new games he doesn't mean Dishonored DLC. Speaking to OXM, Hines specified that the publisher has news forthcoming that is related to neither the Elder Scrolls Online or Dishonored, and that the publisher will be "making considerably more noise" than they did in 2012. "We will be announcing new stuff and making some noise, and I think when we get the chance to show you guys what we're up to, that you'll sit up and take notice."
There are a few possibilities: Fallout 4 is widely rumoured to be in production, and Bethesda was hiring for an unannounced next-gen title back in February. Elsewhere, there's the long given-up-on Prey 2, the rumoured Fallout MMO and of course, Doom 4, which is similarly unlikely to release any time soon because it looks to be in development hell.
So, Fallout 4 then?