I received the via email:
CNET Networks, Inc announced today that it has acquired certain assets of MP3.com, Inc.
Please be advised that on Tuesday, December 2, 2003 at 12:00 PM PST the MP3.com website will no longer be accessible in its current form.
CNET Networks, Inc. plans to introduce a new MP3 music service in the near future. If you would like to receive email updates on this service, including an invitation to a special members-only preview, please sign up here.
I then went looking for a press release of some kind and was unable to find one, however, if you go to http://mp3.cnet.com, you will see that they are indeed coming soon with a mp3 service. So I started looking at the message header and it does appear to have come from mp3.com, so it's most likely true. MP3.com is no more :-(