Fallout 4 Trailer HD (2015)

Fallout 4 is announced by Bethesda Today June 3rd, 2015.
preorder data on same day from Amazon.com says it will be available on DEC 31st,
but www.fallout4.com will most likely provide better details as time goes on.

The confirmed setting is in Boston, Massachusetts; this confirmed from the trailer released on June 3rd of 2015, as well as Gamespot. It shows the Statue of Paul Revere and the USS Constitution in the trailer as well, along with the Boston State House with its unique Golden Dome. Scollay Square, the Bunker Hill memorial, and Fenway Park are also visible in the trailer.
Vault 111 is likely to be somewhere in this region, as it was seen in the trailer. Further, a character wearing the Vault 111 jumpsuit carrying what looks to be a modified laser rifle or possibly an assault rifle can be seen meeting a dog and starting on a road leading away from the camera, a motif seen in various previous installments.

The setting will also include mountains and the outlands of Boston's city limits; also Boston contains tall skyscrapers unlike Fallout 3 and New Vegas. The time period of the game is unknown but on trailer footage suggests that the game takes place after Fallout 3.