Professor Eric Goldman has a post up at his Technology & Marketing Law Blog with an important update on Perfect 10 v. Amazon.com, which I blogged about last May. Specifically, the Ninth Circuit issued an amended opinion Monday that reverses itself on the issue of which party has the burden of proof on a fair use defense in a copyright preliminary injunction context. As Professor Goldman sums up: In the original Ninth Circuit Perfect 10 v. Amazon ruling, the court put the burden on the plaintiff to disprove fair use as part of its PI obligations. Now, in an amended opinion, the Ninth Circuit has put the burden on the…