A new set of campaigns is in the works now. While the first campaign was played from Roman perspective, this one is played as the Carthaginian commander Hannibal. Player gets to invade Iberian coast and then advance towards heartlands of Rome, fighting many historically significant battles along the way.
The first scenario from that campaign, "The Arrival", is preliminarily available in both the free and paid versions of the game (version number 1.2.0 - that's already available on Android Market, on Amazon Appstore the updates are pending Amazon approval so it won't be until next week or so).
Highlights of the new campaign: New units will be introduced! First unit, Longbowman, is already available for playing in "The Arrival". It's the first actual long-range unit in the game, having firing range of 2 hexes. Also, a couple of new terrain types are in mind. Village is a bit like a town (you can heal units there, and you get a couple of hexes visibility around the village), but you can't get income or create new units. Marshland is slow for moving and gives a slight defensive penalty.
So, the bottom line, brand new game content is definitely coming up :-) But it's just taking a little while to get it done properly. New units must not mess up the overall gameplay, but to blend in nicely.