I'm the biggest 40k freak here, so it's good to see #2 
http://b.imagehost.org/0341/dow.jpg
http://b.imagehost.org/0341/dow2.jpg
http://b.imagehost.org/0341/dow3.jpg
http://b.imagehost.org/0341/dow4.jpg
http://b.imagehost.org/0341/dow5.jpg
The intel (gathered from the preview and an interview with Producer Mark Noseworthy in the same Belgian magazine, PC Gameplay):- Uses the Essence 2.0 engine with Havok physics, all optimized for DX10 and multicore support.
- Units also use CoH-like unit AI for awareness and pathfinding to find cover and such.
- While DoW 2 shares the same (upgraded probably) engine as CoH it won't be "CoH in space", while soldiers in CoH will ask themselves if flanking the enemy is the right option, in DoW2 it will be more like Space Marines asking themselves if they should use their jetpacks to jump over an Ork squad to attack them in the back. Different settings, different kinds of warfare.
- Preview only showed a destroyed city landscape, akin to DoW (but more detailed), other tilesets will offer deserts, jungles, mountains and other cities.
- Only the Orkz and Space Marines were revealed, more races on the way obviously and to be to revealed later this year (though how many isn't known).
- Co-op campaign for both the Orkz and Space Marines, apparently not for the other to-be-revealed races.
- Relic wants to give players rewards at the end of a mission like wargear (armor, weapons, rare objects); "Let's pimp out squads with cool stuff!", you will see these items in-game as well of course.
- You'll fight your way through the campaign with the same squads.
- A squad leader (one or several?) will need to survive if you want to complete a mission; you really have to look out for your squads and don't treat them like cannon fodder.
- The campaign lets Space Marines operate from a spaceship, you'll get a view of an underlying planet and you'll be able to choose from different missions (which are tagged with difficulty colors, green, blue and red).
- Certain reward items won't be usable at once in the campaign, so they'll be taken back to the SM spaceship for research.
- Release in early 2009 or later.
!
To say otherwise is a clear indication you haven't played both.
It's this constant push to make MP games shorter by adding finishing units that cheese me off, SC got it just right, most MP games are over pretty quick without the need for super units or crazy game rules.