I want it to be on this Console generation. I remember in some interviews the developers of Skyrim were saying they were thinking of waiting for the next console gen to release Skyrim. I don't want that to happen with Fallout 4, I don't want to have to buy another console for a very very long time lol.
But as for content in the game, I'd like to see rideable vehicles and maybe even some Elder Scrolls references, for example you take the Wacky Wasteland trait in Fallout 4 and a Dragon appears in the game. xD
Or, A more wintery/jungle-like Fallout game, that'd be cool.
EDIT: OH, or an HD remake of the original Fallout. With or without it being an FPS.