Hi, vault dwellers!
So, it has been "hinted" in the concept art, the return of aliens in Fallout 4, and it wouldn't be that big of a surprise, because they are a nice addition to the wacky 50's post-apo-wasteland.
Personally, I would be happy with a crash site, where the player will be able to find a powerful alien blaster and some scattered ammo - exactly like F3. But, I would love if they did take it further and included a secret military facility, small or big, where a faction collected some aliens to harvest their DNA and technology, for their own benefit.
How would you like to see them included, just in the vanilla game?