Well the great news today is that Relic have a sequel in the works, which apparently combines the best of Dawn of War and Dawn of War II.
PC Gamer actually saw a demo game and were able to give some good concrete details.
From what they saw, the epic battles that made the original so good are back, as is base building and resource gathering! As per the trailer (below) there are three initial races - Space Marines, Eldar and Orcs. If you want to play the Campaign, you will play as all three races as each one makes planetfall.
Like Dawn of War II, Elites play their part, plus now there are large Walkers like the Imperial Knight - but be careful using these large machines as they can overheat.
Cover, all important in the first Dawn of War, returns - so get your Devastators in cover and watch for approaching Assault units. I imagine Eldar will be deadly in close range, where the Orks will swarm and the Space Marines will have good ranged power.
This looks excellent and I can't wait for this to be released!