Civilization V: Brand New World explaining the mechanics behind ideologies and policies.
The expansion includes a revamped Policies page featuring two new categories - Exploration and Aesthetics - and the Ideologies, a new feature in which a modern civilization picks one of three ideologies which are basically the secular version of religions. The player then picks Tenets, which, like the Religion's pantheons and beliefs.
The first dev diary can be seen.
Civilization V: Brave New World will be released on the 7th July 2013.