I think they should come out with a Fallout Online since there are still 47 states left after the Nuke wars happened and they already have the graphics and the otheres things needed to make it online.
the Races could be Humans, Ghouls, (sees how they play a major roll in the games), Super Mutants (play fall out 2 and you'll under stand why), the basic character configurations whould be from Fall out 3 as well as the armor, weapons, ammo, and items. as fro regeneration and lockpicking can still be used in missions and tresting up if no stimpacks are avail.
these are jsut some things that can make the game happen.