Some developers like to share their products before they release and give consumers a taste for the greatness to come, while others like to build anticipation and hold out on a much deserving demo-o-greatness (here's looking at you Assassin's Creed). But good thing for us is that Ensemble Studios is all about showing off the goods.
Behind the mysterious "closed doors" of E3 during a Halo Wars demo, Joystiq learned from Halo Wars producer Chris Rippy that a demo is in fact planned to release "for sure before the game comes out". Ensemble Studios' generosity is probably due to the fact that they want to convince the masses that not only is Halo Wars teh greatness, but that their control scheme is teh greatness too. But you're in for a wait fanboys, because Halo Wars and the promised demo are penciled in for sometime in 2008.