Similar to some games when it first came out...

User Rating: 9 | Warhammer 40,000: Dawn of War - Dark Crusade PC
It appears as though Dawn of War came out around the same time as the Battle For Middle Earth. Both games share similar gameplay, only they have a slightly different element of customization. Dawn of War, allows you to customize your army by painting the figurines (just like one would for the board game). The Battle for Middle Earth games allow you to make a custom hero, with custom abilities unlike Dawn of War (however a hero creator would not be as flavorful for the Warhammer games). Both the races of the games act similarly, as well both games have a campaign map with armies being the main vessel to attack a different province. The same strategies in both Battle for Middle-Earth and Warhammer 40k: Dawn of War games apply when in a skirmish or a battle in the campaign (rush wins!).

Hopefully in the DoW2 there are more elements that differ from other games.