(looks for the padlock button) Well lets be Honest, going from Map size to perks is a threadjack.
That said I think its obvious by now that the Fallout map may very well be "physically" larger than Skyrims if they are using the same scaling. To me I suspect the map borders ares most likely going to be
Just north ot Dracut/Lowel
Just south of Frankiln (although you can make a good argument for it being Freetown/Summerset)
the east and west border is kind of tricky, its either Marbelhead or Rockport in the east and at least Fitchburg and Worchester to the west, (and you can make an argument for DLCs extending the game west to Albany in a run up to the Next fallout being in New York City)
Why do I suddenly have an urge to get rope?