I have a friend that maintains a site that was on a JPS/OneMain server. Then it wasn't. If there was a warning that this would happen, it probably went to his tech-hostile boss and went unread/unhandled.

I pray daily (and I'm not a religious man) that my wonderful DSL provider doesn't get bought out (there was a rumor they might get bought by Earthlink). So far, the only stupid thing they've done is change names from rcsis.com to surewest.net. Legions of ticked off users convinced them to hold onto the old domain indefinitely.