I've already pre-ordered it (you should too, if enough people do before launch, we all get a free copy of Civilization 5) on steam, demo is out yesterday.
Played the demo, and even though the demo is fucking huge waste of bandwidth (5GB for 1 level + 1 tutorial level [where you don't get to make any choices on your own]), i can already tell this game is going to be sweeeeeet.
Plus it has multiplayer (which is the selling point for me...fond memories of INCUBATION: TIME IS RUNNING OUT!!!! against my brother on the same computer back in like 1996)