I think they fixed the endless enemies in some parts of World at War. The Bad Guys stop coming after a while if all you do is peek around a corner and pop them in the head for about 15 minutes. Granted, the game then becomes the definition of tedious, but it makes getting through on veteran (
) just that much easier. A notable part would be
When you are trying to take the Peleliu airfield, you come up to a building with two machine guns mounted on sandbags. Roebuck tells you to get the rifle grenades to take out the gunners. The Bad Guys stopped coming around the five minute mark.
When nobody is shooting at you, it becomes immensely easier to complete your objectives.
EDIT:
CoD6 was... alright