Warhammer 40,000: Dawn of War - Soulstorm, to give it its full name, is the third expansion for Relic's PC RTS. New screenshots and a movie have been released.
Soulstorm's a collaboration between Relic and Titan Quest dev Iron Lore, and includes two new races and a new interplanetary campaign spanning an entire star system. On top of that, existing races are receiving new units - the debut of air units can be seen in one of the shots - and multiplayer is getting boosted.
It's due out spring 2008.