Microsoft's online game network will only be down 24 hours for upgrades, although its promised improvements won't be available just yet.
Next Wednesday, at 6:01 am Pacific Daylight Time, Xbox Live will go offline. Not for good, though. Microsoft is merely taking the system down for 24 hours as part of the system-wide upgrade code-named "Tsunami." Once implemented, Tsunami will bring a bevy of new features to Xbox Live, including improved team dynamics, team customization features, new custom-competition options, and MSN messenger integration.
Unfortunately, not all these features will be available after Xbox Live comes back online and users download the obligatory update. "It's important to note that not all features we have announced will be available after the upgrade," read a forum post from Xbox Live Director of Programming Major Nelson. "Most [features] will not be visible until game developers decide to implement specific features into their titles."
News source: GameSpot