Tch, I think Bethesda and their titles are overhyped. I love Skyrim, but it's not got great game-design in terms of level-scaling or quest-progression or anything IMO. Also, Bethesda's writers usually suck, which is true for Oblivion, Skyrim and Fallout 3, so with Fallout 4 being more story-focused with voiced protagonist and all, I have nothing but fear that it'll just shoot itself in the foot with it because their writers are just atrocious.
The mods for Skyrim significantly improve the experience, tailoring an good game into a great game because the player is able to modify its content to suit their tastes and world view. Thus Skyrim can become a gritty environment survivalist game of thrones experience to My little pony/ Thomas the tank engine dragons to a leisure suit larry in medieval armour. To use some else's concept it creates a sense of ownership of the narrative, where it becomes "your game". Bethesda has not done characters well, Bioware games tend to be very much superior in this regard, but fan mods have attempted, with varying quality admittedly, to addressed that in Skyrim.
So the modibility of Bethesda's games are a strong selling point, which means I will wait a year for the mods to be developed, before buying the game of the year edition, etc.