Lots of more building options, but progression wise almost no change yet.
If you like building structures, then the game is absolutely worth playing again for the new stuff added. Building more complex and good looking buildings.
If you like progressing through the game and killing bosses, its not worth picking up again at the moment. The last major update has almost been a year ago, so i cant imagine it taking much longer for Mistlands to drop and add more progression for those that want that.