I mean mainly the original developers!
You do realize that of all the people that worked on Fallout, not very many are working at Obsidian. As far as I know, the only one who is is Feargus. Among those not working at Obsidian are the lead designer, lead programmer and lead artist.
wow! you forgot about Sawyer, Monahan, Chris Avellone, Chris Jones and the others??
also don't forget that when Troika died some from there joined Obsidian too (like Chris)
EDIT:
ah forget Chris, he left the sinking ship in time