Since 2007 Bethesda is the owner of the Fallout franchise, giving them the licensing rights to all future Fallout games from that moment on but Bethesda had also apparently had given Interplay back license to create a Fallout MMO.
The drama started when Bethesda claimed that Interplay had not honored their part of the agreement by not starting on the MMO project at the agreed pace. So Bethesda began the lawsuit to gain the licensing rights back from Interplay and lost (yay~). Had the motion succeeded it is still not sure if Bethesda really wanted to develop the MMO themselves.
So it seems the work on Interplay's project will continue and we will be able to see more of the game sooner as it's being developed. Interplay has won the court battle but the reason why they won is still a mystery. All we know is the judge that made the ruling is Deborah K. Chasanow, which perhaps is a Fallout fan looking forward to a faster development of the MMO?
Source: Gamasutra