I've been following this one for a while. The short story is spammer sues Spamhaus. Spammer wins by default because Spamhaus is in the UK and say US court rulings can't be enforced against them, and so was a no show in court. Spammer goes after Spamhaus domain.
My thoughts about all of this are first, or firstly as they would say in the UK, using Spamhaus blacklists is voluntary. Therefore, Spamhaus doesn't block anything. Individual admins do all the blocking. Second, Spamhaus has no choice except to take a stand. Otherwise there would be a torrent of nuisance suits by spammers. Third, thank goodness the domain is registered in Canada because the US courts don't own Canada either. Fourth, ICANN, even though it is a US entity,is rightly doing its best to stay out of this, as they understanding the broader ramifications.
What happens here will effect the fight against spam. Every time a spammer wins the rest of us lose. And to the folks who buy stuff from spam: You are the root problem. Be more discerning and stop buying from spammers. The world will be a better place. Of course if you are reading this, you are not in that last category. I just wish I could actually reach the idiots who buy from spam.