The ad page for Mothership Zeta indicated there will be abductees from "earth's past" on the ship with you. What characters from Fallout lore, either mentioned or met in previous games, could be on Mothership Zeta?
It would have to be someone not killed or likely killed... maybe not even possibly killed, though that limits who it could be drastically.
It would have to be someone worth mentioning, i.e. someone with a clear name and look to them, or who did something at least somewhat important.
It would most likely have to be someone young enough in the previous games to still be alive in Fallout 3 time, though with "earth's past" being mentioned, this could be dubious, as they might be doing some sort of time barrier/warp plot device.
If it is someone who was never in a game, but is known enough to be recognized or important, who could this be? Who are the people mentioned prominently in Fallout lore but never seen in any game?
My ideas are limited, as I have not played FO1 or FO2 in quite some time, and never played Tactics at all. I would guess Harold if he was not already in the game in another way.
I think a likely candidate would be one of the followers from previous games, like Ian.