In the initial press release, Relic/Sega say that DoW3 will have “the epic scale of Dawn of War” combined with “the customization and elite heroes of Dawn of War II.” They also mention larger units (“super-walkers”) and weaponry (“giant orbital lasers”) than we’ve seen in the games before, suggesting it’s doubling down on the increased scale. If you’re looking for a simple answer as to whether the game is closer to DoW1 or 2, the original is the answer, but it’s certainly shaping up as its own thing.
While the overall strategy of a map will still be controlled by power generators and capture points, just as in the first game, massive units with unique special abilities are how DoW2 is brought into things. They're called elites, and in singleplayer will be collected and upgraded as you progress. They're meant to dominate battlefields single-handedly. Cover is also returning, but simplified so that squads of units capture areas, becoming more resistant to range fire but easier to clear out with assaults.