Colossal Order, the magnificent little Finnish company, release this title on the 10th March.
As a huge fan of their Cities in Motion and CiM2 games, this is the game I've been waiting for for a while now.
On the surface it seems very much Sim City, with residential, commercial, and industrial zones, healthcare, police, fire etc etc etc.
A few teaser vids ...
But there also seems to be a lot more going on under the surface, a lot more depth. Districts, persistent citizens who change with age, dynamic water movement, policies, working public transport, themes, modding ability. And EXPANDING MAPS!
The Dev Diaries have a lot more info.