Unfortunately no. However, you can play the storyline in coop mode as Marcus or Dom. Also, there's an achievement if you play the whole game in co-op as Dom.

Yes, there is one. I just saw an article about it a couple of days ago in Shacknews.com

Gears of War 3 Beta Announced for Early 2011; Uses Dedicated Servers

http://www.shacknews.com/onearticle.x/65911

Call of Duty WAW and the 3 map packs...

GameSpot User Name: mag_sithlord

XBOX 360 GamerTag: mag sithlord008

Region: United States

Time Zone: (UTC-08:00) Pacific Time (US & Canada)

Swearing Level: [Normally] 0/5 depends..

Headset?: Yes; Turtle Beach EARFORCE X11.

I am currently looking for people to play and/or get achievements for the following:

1. Gears of War 2 [With DLC]
2. Call of Duty WAW- zombies [WithDLC]
3. Borderlands [DLC pending]
4. Halo ODST (with Halo 3 Disc Multiplayer)

Send me A FR! :)