I totally agree, 2 is the magic number for this mode. I only played 2 player zombies as well.

They tested with 4 and with 2 players and the majority of the community and the both teams at IW and SHG were in agreeement that 2 was the magic number with AI brought in at times to help via a purchase. When 1 player dies, the game is over. The chance of that happening is very high with 4 players. In zombies, 1 player could finish a level and bring back the other 3. Not competetive at all. Zombies is too easy. This will actually be a challenge. 2 is the best choice they made.

No, it is two only. That could have been AI called in from a purchase made in the support store.

http://www.callofduty.com/message/11473#11473

this will answer all of you

yeah, its all about in game customization. play style, tactics, weapons and attatchments, perks, killstreaks. Not the main focus of the game. The main goal is keep yourself alive and protect your partner. Not mow down enemies cause youre 4 bad ass guys, like zombies or left4dead or nameless other games. They made their game unique in as many ways as they could and they made it perfect. stick with zombies if you want easy.