Let me put you in a situation: You are playing an MMORPG someone posted a very corny message in the chat box. Lot's of other gamers replied messages with "lol" included in it.
Ref: LOL is an acronym for "Laughing Out Loud"
eg: Q: What is the food that you laugh most?
A: LOLlipop
I wonder why COD MW's story is better than 2. Activision might have sent this message to Inifinity Ward: "Infinity Ward be advised, deadline for Modern Warfare 2 is nearing."