If you pre-order Fallout 4, it will pre-load prior to the games release date on November 10th, as Bethesda noted on it’s Twitter account:
“We can confirm that #Fallout4 will have pre-loading on Xbox One, PS4, and PC so you have a few days to download the game before 11/10”.
What this means is that the game will be fully installed prior to it’s arrival in stores, and thus on November 10th, you’ll be able to play it without delay.