In perhaps the final hurrah for COD4 (before the next wave of Xmas FPSs hit the shelves), you can snag the Call of Duty 4 Variety Map Pack for 50% off (400 MS points).  To throw in some additional love, they will be throwing in double XP all weekend as well...

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Heads up that this weekend from Friday the 12th - Sunday the 14th on Xbox Live (PS3 event will be later, closer to the 18th), we’ll be having Double XP all weekend long on every playlist. In addition, we’ll be doing some DLC promotion on the Xbox Live Marketplace that will allow you to download the Call of Duty 4: Modern Warfare Variety Map  Pack for 50% off, which means you’ll be able to snag all four maps for just 400 MS points. 

[Source:  fourzerotwo]