Everyone is in generall agreement that the next DLC will be Skaven vs Dark Elves.
As for the Skaven LL, the vast majority agree that its going to Throt the Unclean.
And for the Dark Elves LL, some are expecting Malus (i will be disappointed, he needs to come in Part 3 to reach his full potential) or Rakarth (the most likely option.)
But what if CA Troll us?
It wouldn't be the first time.
What if CA decides F this, lets create a dual Assassin Lord Pack. Shadowblade vs Deathmaster Sniktch. Besides the units they would specialize are already in-game. So its just a matter of buffing their stats and maybe added a few Elite variants and Lord Versions.
Personally i would be disappointed if this is the case. But i cannot deny it happening either.