Not only do we get the treat of new maps for Call of Duty 4, we get a Double XP Weekend. This is your opportunity to grind out some more prestige levels.
Go forth and game! Now!
UPDATE: Xbox Live seems to be having "issues" currently. Our best guess is that lots of people (like everyone at G4) got home from school/ work and is trying to download the same map pack at once. These issues also extend to the forced download on the CoD4 system update, which means no online play until you get thru. Sad face.
UPDATE v2: Keep trying over and over... took us about ten minutes of refreshing and retrying the download to get it to start. See you online.