Split screen... I suppose that would be quite ugly view. It would think to have sort of windowed screen, when you can choose and arrange different management screens, like current researches, manufactures, transfers, bases, soldiers, etc, like everything you need to watch in progress or need to wait for something. But that would be totally different UI design.
Actually I tend to support this idea, though it should be thought of thoroughly, in order to become very handy and useful. And this will change game athmosphere greatly, and it won't be xcom anymore.