As recently speculated, the next entry in the Total War series will be a return to Rome. And as expected, The Creative Assembly will be pushing the series beyond the enhancements brought about in the Shogun 2 series. The game will re-introduce individual traits, but also add unit traits. The moral decisions introducted in Fall of the Samurai will be enhanced into logical chains that will affect the direction of the campaign. The goal is to introduce a story like aspect to the game and take the sweeping campaign to a more personal level.
There is much more and you can read about it over at IGN.com