In a move that will undoubtedly annoy users, Comcast has sent email to its customers (some weeks ago) informing them that they have until next week to begin the transition from their @attbi.com addresses to @comcast.net.
Although it isn't costly for the company to maintain two domain names, it is apparently too much of a dilution on the Comcast brand to have customers receiving email on attbi.com. As such, the addresses will no longer be usable for receiving email after December 2004.
However, in order to move the process along, the company has released a Transition Wizard to change the user's settings appropriately. This includes setting the return email address as well as the new mail server names.
Although the press reports (such as this one from CNet) focus on the next week deadline to run the Wizard, the only requirement is that users change their outgoing and incoming mail servers by next week, as the existing attbi.com mail servers will be turned into forward-only systems.