On top of the new Champion role the expansion will also be adding:
*A whole new kind of human player! A Champion player controls a single modular, upgradeable unit of one of the four races (only the human champions are implemented so far). Let your friends control these in multiplayer or add directly-controlled champions into the other player slots in your singleplayer game!
* Several new sub-races dwelling in the backwater parts of the galaxy for your champions to interact with (2 implemented so far).
* Modular fortresses!
* 9 new bonus ship classes (to be added soon; please be patient on these).
* 3 core AI guard posts and one new minor faction (both to be added in the coming months before release)
* New AI types.
* New Map types.
* A large amount of new music (to be released when the expansion fully launches).
The whole expansion is surprisingly cheap, $5, and if you pre-order it you can get it for $4 and you will get instant access to the beta. They also have a demo available here, it is the furthest demo down on the page. The expansion isn't standalone though, so you will need the base version of A.I. War which is pretty damn cheap and goes on sale very often. The game isn't for the faint of heart, especially with the huge amount of options there are when starting a game, but it is one of the best space strategy games that I've ever played. Ancient Shadows will be coming out in October. Thanks for checking it out.
More info: http://arcengames.com/w/index.php/aiwar-ancient
-Written by Sean Cargle