Apparently someone didn’t learn there lesion from the DMCA. The DMCA was designed to stop people from creating copying devices for copy protected content. It has currently been used to sue manufactures of generic ink cartages (thought they lost that case), and by Blizzard to sue BNet. That wording can denote anything when you have an army of lawyers.
I don't think this is a loss for anyone really. Grokster was apparently openly asking people to use them to steal things - and the Supreme Court acknowledged that. Something like Bittorrent, which is only intended to help copy large files, is still fine under this ruling. Really, if the Supreme Court hadn't found for the RIAA/Motion Pictures, then they would have gone off into congress and bought themself a more stringent law. Instead, the current law just got a little nudge.