It seems the PlayStation Network isn't the only console gaming service that is currently dealing with hackers. Though it seems on a much smaller scale, Microsoft is warning users currently playing Modern Warfare 2 that they may receive "title specific messages that are phishing attempts."
Phishing is used to trick users into unveiling personal data to allow someone to use it for their own person advantage. There's not much else revealed on the Xbox Live Status Page, and this shouldn't affect your gameplay, its more of a just a heads up on Microsoft's part. Microsoft states they are aware of the problem and are currently working to resolve it.