They are using a modified version of Unreal Engine 3. (Much like X-COM, and its upcoming sequel.)
So this is less of a port, and more of a deployment to a platform that widely varies in terms of performance. And this is much easier to do when your graphics aren't so "next gen".
So this is less of a port, and more of a deployment to a platform that widely varies in terms of performance. And this is much easier to do when your graphics aren't so "next gen".