Not likely at all. What is likely is that Bethesda loses the case and Interplay gets to continue developing (or fucking up) the MMO.
Really doubt Interplay will win back the franchise rights, that would be a miracle. And here's a funny thought, say they did. What then? Would they go back to the isometric perspective and turn based combat of F1 and 2? Sadly, I doubt it. However, they could make a bigger, shooter-like Fallout game for the consoles and a lower budget Van Buren-like game for the PC crowd. But that would be more than just a miracle, that would be divine intervention.