Call of Duty: Modern Warfare 2 Multiplayer Gameplay

Because at the end, it says "Modern Warfare 2". That, and if you click on the video link, you'll see that it's a direct feed from Infinity Ward's youtube channel. BELIEVE IT (lol, Naruto).

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CoD5 was my favorite

How is that so? The only real difference is that it's somewhat harder to kill people, there are two more game modes in WaW (CTF, War), and some maps have tanks! Not to mention, CoD WaW has a lot more maps (Map packs; epic win)