If you're a fan of overly fancy knights based on medieval France you'll be delighted to hear that Bretonnia will be joining Total War: Warhammer's rapidly expanding faction roster on February 28th. Bretonnia is technically already available in game, but it isn't really fleshed out so you cannot choose it as your starting faction on the campaign map.
Once it does become fully available, however, Bretonnia will come with three Legendary Lords (King Louen Leoncoeur, Alberic of Bordeleaux and the Fay Enchantress), a variety of unique quests that relate to each specific Lord, as well as a whole bunch of updated units to toy around with. Basically, it will bring with it everything you expect to see from a 'proper'Total War: Warhammer faction.
On a slight side note, if you've somehow landed here without actually owning Total War: Warhammer, you're in luck as the currently ongoing Humble Monthly bundle is offering it for a measly $12! Besides featuring the biggest discount for Total War: Warhammer ever, the Humble Monthly bundle will also bring with it a bunch of mystery games at the beginning of March, so I would definitely suggest you grab this one if you have even an inkling of interest in Warhammer. Just make sure to unsubscribe if you're only doing this for Total War: Warhammer!
And finally, if you're interested in my thoughts on Total War: Warhammer you can find my detailed review by heading over here. Long story short, "Total War: Warhammer is a crossover between two franchises I've enjoyed for many years now, and I'm delighted to say that it manages to be faithful to both sides, and most importantly, an actually enjoyable experience on its own!"