Creative Assembly will later this year release Rome II, a proper Total War Game. They'll also, presumably, one day take the wraps off a Warhammer title. As of today though there's another Total War game coming, and it's a weird one, because it's not the Warhammer game, and it's not the next true Total War game either.
Called Total War: Arena, it's more MOBA (DOTA, League of Legends) than grand strategy, putting players in control of only a few units. It's free-to-play, and those interested in beta testing it can head here for more info.
I'm not sure how I feel about this. The regular Total War games are maybe my favourite series on the planet, but the last attempt at creating a spinoff - the touch-based Total War: Battles - fell a little flat. Without seeing thousands of men being sent to their deaths across rolling green hills, the series loses its core appeal, and with Riot, Valve and Blizzard already fighting over the MOBA genre, CA and Sega certainly have a fight on their hands to create something worth people's time.