Below you will find a bunch of new details of the game, including info on the possible return of the "zombie mode", and info on the game's co-op limitations. Here's the info, from the latest issue of Official Xbox Magazine.

• You will be fighting the North Vietnamese Army in certain missions.
• You’re an off-the-grid, best-of-the-best badass -- like John Rambo or John Wayne.
• Vehicles will return, but “not in the way you remember them from WaW”.
•  There will be “dedicated co-op” with separate levels.
• Treyarch changed the subject when the mag asked about World at War’s hugely popular Nazi Zombies, saying: 
  "We really like the Zombie Mode, and as I mentioned I can't talk about the co-op mode other than to say one of the reasons we love it so much is that it feels like it was a fan adopted mode, made out of passion of a lot of the team members here."
• Treyarch's considering a multiplayer beta.
• Changes are being made to the matchmaking to “make it easier for [players] to get into games with their friends.”
• Create-a-Class 2.0 will allow you to customise yourself like never before. This should include kit and appearance items as well as perks.

Source (WePlayCoD)...