Since several cases have come to my attention recently of domain registration being borked up by a provider, or due to some threat of legal action, as in this case, I will reiterate my suggestion, originally made on May Sat 7th 2005:
of saving IP addresses with bookmarks, in addition to domain names, so that when domain registration is discontinued for some website for some reason, the website can still be reached through its IP address (assuming that this has remained the same).
Necessary for this is some mechanism for the user to indicate that the website he was redirected to by a bookmark was not the one he intended to visit, and hence try the IP instead. I suggested to give the user a button in the status bar, maybe labelled "IP", that shows up when he's used a bookmark. The user can then decide whether the page that showed up is the one he was looking for, and failing that, can press the IP button to get to the IP address of the original server (plus the rest of the URL, i.e. the path on the server and/or parameters for php, perl or other (database) scripts).
This will lead to IP-hogging as a new phenomenon, but we're no worse off than we were before, as long as domain is given precedence over IP.