So I spent a few hours with the game. Did about 2 single player missions and a few skirmishes. Here are initial thoughts.
This game may look like Dawn of War with WW2 setting and a new coat of paint but its not. The game is heavily tactical and rewards the players who has his squards run for cover and flanks enemy positions.
First lets examine the differences between CoH and DoW.
CoH almost completly does away with universal upgrades. There is no "Upgrade Armor +1". Your troops become hardened through experience which is nice. Once you upgrade your headquarters, individual squad upgrades are availble like sub-machine guns or panzerfausts.
The "Talent" (I am just calling it talents like WoW because I forgot what they are called in CoH) trees add a new layer to gameplay. You earn talent points by being in combat. Save enough points and you can put them into new skills or upgrade options or even reinforcements. Americans and Germans each have 3 different and distinctive trees they can each go down. The Americans can choose to upgrade the Infantry, Airborne or Armor while the Germans can pick to upgrade their Defense, Offense or Moral.
There are now 3 different resources. The map is split up into several "zones" each with a resource. You MUST have all your zones connected to your HQ or it is considered "out of supply" and will not give you resources. Obviously, this means that you must fortify and guard each of your resource points.
Like I said, the game is much more tactical. Moral is gone, replaced with a "Retreat" option. If your troops come under heavy fire they will become "pinned" and start crawling. This is sort of the equivalent of "Squad broken!". At that point you would retreat your squad out of there as retreating makes your squad faster and give it a defensive bonus. If you don't then your squad will die and you will have to waste more resources getting another.
In DoW, you could charge a fixed defensive emplacement with a mob of troops and come away without a scratch. In CoH you are forced to use flanking tactics or armor to destory bunkers or machine gun nests as they will rip apart infantry.
Armor now hav "hardpoints". This is a great new feature. Tanks have much weaker armor in the rear so flanking tanks will have a definite advantage. Tanks can also have certain parts like their gun, gunner or engine destroyed/killed and will require engineer teams to fix them so they can move again.
Thats all I can think about at work. I'll post further impressions later. It's a GREAT game so far!