Bethesda has purchased the IP for Fallout from Interplay … but Interplay is still making the Fallout MMOG. That makes them licensees of the IP they used to own.
::blink::

It’s a strange world.

In a special clause of the purchase agreement, Interplay agrees that “full-scale development of its FALLOUT MMOG will commence within 24 months of the Effective Date of this Agreement” and that “Interplay will have secured financing for the FALLOUT MMOG in an amount no less than $30 million” within that time frame or forfeit its license rights for the MMO.

Similarly, “Interplay must, in addition, Commercially Launch… the FALLOUT MMOG within four years of the MMOG Development Commencement Date, or again, “Interplay will immediately lose and permanently forfeit its license rights under this Agreement.” When and if the Fallout MMO launches, Interplay has agreed to pay Bethesda 12 percent of the game’s sales and subscription fees for the use of the Fallout IP.