you can play several players together in campaign mode. And yes, it's WW2, but soldiers move and run like in cod4 so i guess it's pretty good, also the multiplayer mode is a lot like cod4 you have perks and if you get five kills you get an artillery strike, and if you get seven kills you get dogs.
Yeah keeping the gameplay of 4 with going back to WW2 sounds great. I always loved playing the first 3 CoDs in WW2 setting!! But Im getting GoW2 and just got Fable 2, so Iwon't get CoD5 for a while...but I am planning on getting it.