Yes, it's time to officially let go of Vault 101 and embrace something different, for a prominent shot in the Fallout 4 trailer teased the presence of a new vault, 111. It's pretty reasonable to assume that the new protagonist hails from this vault, though beyond that, nothing is known about a) what the interior of the vault looks like or b) how much the vault itself may figure in the game's plot. Whether this will be especially important in the scope of Fallout 4 remains to be seen, but it's still an immensely tantalising tease nonetheless.