There's a new piece of paid-for DLC coming to Total War: Warhammer on October 20, and it brings with it two new Legendary Lords (complete with new quest chains, magic items, and their own skill trees), two new Lord types, six new units, and some additional content (the press release also mentions new content for all players, not just paying ones, so expect more news on that front "soon").
You can see the trailer below for more intel, and there's this little writeup from CA and Sega that details the new characters and content:
The King & The Warlord introduces two new Legendary Lords to the game: Ancestral heir of Karak Eight Peaks, Belagar Ironhammer who leads the Dwarfen faction of Clan Angrund, and Warlord of The Eight Peaks Skarsnik, leading the Crooked Moon Tribe. This new Lords pack also offers a wide array of new campaign bonus, new battle maps, new lords and some exciting new units including a fan favourite for the first time in Total War: WARHAMMER, Squigs!