http://www.reddit.com/r/falloutlore/comments/38ekf0/fallout_4s_vault_111_is_located_nnw_of_brookline/ did some research on the location of Vault 111 and came up with some pretty convincing evidence that the location is near Brookline.
his is a better choice in that you have roughly simular land structure but theres no houseing there in the direction that seems to match the direction indicated by the Vault entrance (if you use it as a compase rose), and no Iron tree main power lines, but theres at least three places roughly in the most logical sighline (and recipical sight line) I think could logicaly have gotten a nuke. (an old Arsenal that was closed and eventualy removed in the late 60s, a national Guard armory that was formerly a US army facility, I think It was also removed, and a (now closed) Federal reserve currency reserve storage vualt.(closed in 1970s)
Not bad.
So the people at reddit apparently think they know where the Vault is, along with the big tower visible in many locations, as well as the garage.
Here is their work
http://imgur.com/a/lFIxR
And their map
http://i.imgur.com/EzaTAU9.jpg
They make some pretty convincing points about the rough locations of things.
-Vault 111 appears to be located in Whitney Hill Park, which is itself located inside Watertown.
-The massive tower seen in most shots appears to be part of The Institute.
-The nuke seems to have hit somewhere around Brighton.
That is pretty convincing. I'm not sure how much information like this I want to know before playing the game, though. If this much of the map can be pieced together just from that trailer, imagine how much more will be figured out from what they show at E3.