There have been better
The main problem with it is that the campaign isn't all that different then it should of been. While they allowed you to play as more races, they took the Emperor's finest out as well, meaning you could play as everyone but them. This means that there are now two campaigns, good and evil, although they are both quite short, only six missions each. For the good campaign it is just an introductory for the new race, the Imperial Guard, which were used a few times in the first one, but are now their own army. The normal troops are pretty terrible, but work well in large numbers. They also get commanders which go together into a squad and are usually more than a match for most enemy troops.
The campaign for the Imperial Guard is quite easy, until you reach mission four where you are forced to escort a Land Raider and hope it doesn't get destroyed like it always does. While it has an honour guard of Ultramarines they are great at defending it until they fall which when they do, it will get destroyed and you will need to start again. Thats on the easiest setting and its still hard. The rest of the campaign though is easy, but the last levels are great fun to play as you get to use the Titan's guns, which will destroy anything they hit.
The online has had a few maps added, nothing special but most people will play as the Guard as once they get full Kasrkin armies, they can be very hard to beat. As can Chaos with the new Preadaotr upgrades, which make them immense on vehicles and heavy infantry. All the old armies get new units too, Marines have the Chaplain which is a powerful melee atacker but can't join units. Chaos have Khorne Beserkers which are also excellent at melee and immune to morale. Orks get Mega Armoured Nobz which while slow are again great at melee, but also quite good at range. Eldar get Fire Dragons, which can melt all but the hardest vehicles and get up off the ground faster than most troops. All most be used properly otherwise they arn't too effective, but if used with the proper units and timing, can prove deadly.
While not as great as the original or Dark Crusade, it is a good attmept at making the classic strategy longer.