The homages to H.P. Lovecraft in Fallout games have always been there, culminating in the wonderfully creepy Pickman's Gallery in Boston.
Now that we're officially in New England with FO4 I think it'd be cool to go all the way. Expand the borders a bit to the North and let us explore Lovecraft's New England. Imagine what must be lurking in the ruins of Arkham and Miskatonic University! Or how the deep ones would respond to the collapse of the surface world around Innsmouth. Or how the inbred, backwoods natives of Dunwich might not even have noticed there was a war.
Don't know if it'll ever happen, but I'd sure love to see it.