SEGA has confirmed that next week will see the addition of the Bretonnia race for Total War: Warhammer, with the group joining the battle on February 28th. They are a free DLC for all players and will add three new playable legendary lords, as well as unique units. Those who have Total War Access will receive the Bretonnia option on February 27th.
Alongside this release an Old World edition of Total War: Warhammer will be made available at certain retailers too, which is the up to date version.
Source: Press Release