What do you hope to see in Fallout 4?
I want to see a DLC Expansion into New York that is situated south of Boston.
I also want to see more interaction with the world. In the same vein that we have seen with the difference in content between Oblivion and Skyrim.
I want to be able to rebuild the world! Not just in actions but scavenging metal and forging it into parts for buildings, maybe even make your own town with the choice to invite the people you want to live under your mercifull, or brutal rule. Placing who you want into the jobs you require like farmers, sherrif, store keepers, scientists, or in the alternative raiders, slavers, and enforces! Placing the buildings you want where you want into the space you have selected and protect it from those who would do it harm.
You could make alliances, and set the laws of the land that would greatly affect who attacks and what happens dynamically, including what supplies you get and how people see you in your travels!
Will you lead a town who follows you like a religious cult, a band of ruthless slavers who pillage nearby towns rather than align with them, or will you build a trading outpost, a scientific community, or just a community of people who endeavour to have a better life, or a mixture? the choice would be yours!