According to anti-spam lawyer Matthew Prince, 'there may be some time before ICANN is formally ordered to shut down the Spamhaus domain, but make no mistake that ICANN's lawyers will be considering their options beginning first thing Monday, if they haven't already begun the conference calls tonight' ... 'In the end, [ICANN's] decision is likely to be much more about setting a general policy than the specific details of who Spamhaus is or why they are critical for the Internet. ICANN will desperately want to stay out of this dispute, but they are subject to U.S. law and they will probably have attorneys who will argue they need to follow it. All it will take for this to end badly for Spamhaus is one lawyer at ICANN getting a little bit spooked and Spamhaus could lose not only it's .org but potentially any other TLD that ICANN controls.'

This is interesting -- if Spamhaus is forced to close down its domains and US-based mirrors, that will mean that the SBL and XBL blocklists will be down for a while, too. Typically those are used for up-front blocking, and if my servers are any indication, they take care of 75% of incoming spam before it hits any more CPU-intensive filtering.