The multiplayer is im sure just racing, The co-op bit is called 'Legends of the Wasteland' while your playing the main game your hear through newspapers, radio etc about these legends and there missions, and these are the missions you do with a friend. Think
theres 8 all together.
Only MP Is the races with cars.. No Co/op per-say a few co op missions like two worlds co op .. still cool but for ID and the creator of the FPS sad to see no dm or team dm or shooting game types ... sad but we shall see id tech 5 will be the unreal 4 killer
like before when doom and quake engines id 3 and id 4 ruked the game world which is great and finally no more unreal look alike games