Call of Duty XP is opening up to the public today in Los Angeles, and despite the dizzying number of events and attractions, the real star of the show is the chance for fans to get their hands on Modern Warfare 3's competitive multiplayer mode. If you're not in town for the festivities, though, fear not: We already have a thorough video demo courtesy of executive producer Mark Rubin, and we have the chance to play the game for ourselves. So take a look at the video below, and read on for some news on what's new, what has changed, and what's gone in Modern Warfare 3 multiplayer.

What's New

Perhaps the biggest addition to multiplayer in...