I hope they make a BAF of Darkseid, Doomsday, and Mongul. Not necessarily right away, but here and there.
I really don't think we need to see Darkseid or Mongul for a long while. I'd rather get other Superman foes like Metallo (with attachable mechanical limbs/weapons in the same style as Metamorpho).
Doomsday, however, is too small. With Darkseid and Mongul it's less obvious, but Doomsday fits about as well as Joker does.