Obviously, this is a huge win for everyone out there that pirates music, it will make it a lot more difficult for the RIAA to get your name and home address.
More importantly, this is a huge win for ISPs. It restores the security ISPs had been given previously in the 80s from the Communications Act–immunity from their customers. The Communications Act was pushed through Congress by the Bells to make sure they couldn’t be sued if someone was using their phone service to do something illegal. Just like the USPS isn’t responsible if you use the mail to commit a crime, the phone company shouldn’t be responsible if you use the phone to commit a crime. This trial restored the protection ISPs had previously assumed.
ISPs shouldn’t be responsible to do jack if you use your Internet connection to commit copyright infringement–without a warrant.