I found this statement from Xbox LIVE's Major Nelson
Many of you might have noticed a bevy of problems facing Xbox live over this past week: An unresponsive marketplace, the inability to recover a gamertag (or even sign in), and aggravating matchmaking wait times, to name a few. Major Nelson
issued a statement last night explaining that while there have been no complete outages of the service over the past week, "problems like this are not acceptable," and that they are working to get the service back to normal. Sadly, no time frame was provided on when repairs to the service would be complete.
There's been no official statement on why the service has been so shoddy lately, but if we were the guessing type, we blame it on the holiday season. We're sure that tons of people found a 360 under their trees (or candles), and immediately tried to hop online; only to collide with the millions of vacationing gamers who were already playing. Technology has come a long way, but the internet can still only hold so many racial epithet-slinging Master Chiefs before things start breaking down.