I realize with the Fallout 4 trailer and all that I'm probably gonna get a lot of my RP stuff jossed to some degree. Hopefully not too much- I mean, Boston's a long way away from DC, we may not hear much about the Capital, but there's always a chance of Brotherhood of Steel interaction up there, plus Madison Li is written out of FO3 with "she packed up her bags and left for the Commonwealth", so who knows what she might have to say about things that've happened if/when she's encountered.
I am going to approach the interim wait with the attitude that whatever FO4 says or doesn't say about Capital Wasteland-area canon only necessarily holds true for the Fallout universe without contamination from Milliways. The instant cross-dimensional patching began, the Trousers of Time forked. Events in Ellen's leg are not necessarily contradicted or written out of existence. They're just the events that happened because the Lone Wanderer ran out of the tunnels under Springvale School and into the end of the universe, and then kept hopping back and forth. The other trouser leg contains pure-strain canon. Events that occurred there that I like enough and think are plausible enough to have occurred may very well have occurred the same way in the Milliways leg, too. Events that don't make sense with what I've established are another story and stay in their own leg.
If I'm jossed about something seriously historical, or about how this, that, or the other thing worked in-universe, I'll deal with it. (The historical stuff is a real possibility given how much footage the trailer shows of pre-War scenage, and given that the audition script Kotaku got hold of several months ago included people talking about grandparents before the Great War.) But anything that contradicts any events after Ellen ran from the giant ants and into Milliways is subject to the Trousers of Time approach.
I should note that Ellen will consider the other leg of the Trousers to be the weird alternate universe, because no one ever says "Oh, yes, I see what you mean, your reality is real and mine is just a pretend splinter thing" without their universe being defined by more suckitude than Curtis Everett on a bad day. And even then it's iffy (ask some of the characters from certain parts of Dragon Age Inquisition about whether certain things were Real or just Bad Possibilities That Should Not Have Been).
Also I will fight to the figurative death to keep my version of the Capital Wasteland Brotherhood of Steel, kthx. Just a warning.
... that being said I really need to find some way to get Ellen to offer more of her chaplain/counseling abilities in Bar, or in other people's worlds if need be, not just her freakish Scourge of God fightin'-and-killin' skillz. I've been wanting to put her forward as an alternate offering for people who might have spiritual needs that don't map neatly to 'oh, yes, you want $DEITY, S/He is over there' for a while now. I'm just not sure how to go about doing that.