As you might have noticed, XBOX Live has been having seizures over the past few days. Either Microsoft sold a lot of 360s this Christmas or the Live team started their holiday too early. Regardless, the 360 experience has been far below par over the past few days.
Per this post by Major Nelson, they are working on it. Please be aware that when XBOX Live has issues, the 1337pwn XBOX Live Friends List widget may also be affected.
Thank you for your patience. Have a happy New Year!