Majin Goku

Halo Wars takes place in on Harvest (It should take place there). It's when the humans first meet the Covenant, or their first deadly incounter. If you've read the novels you would know. That or it would be Reach, because the Spartan IIs don't fight the Covenant in their MJOLNIR Armor until the battle at Reach. So it would most likely take place at Reach. It is supposed to be a RTS like Command & Conquer. It's not yet known if you can play the Covenant or the Flood. I'm putting my money on it though. The trailer looks great (that isn't real gameplay) but it looks realy fun. It pre ships on December 31, so it most likely isn't coming out until 2008.
Hope I helped.

georgedlee101

I played a demo of the game it rocks