Well, I haven't had a chance to read the ruling yet, but it appears that the SCOTUS has unanimously gutted the Sony decision and made software companies potentially liable for infringing uses of their software, regardless of whatever significant non-infringing uses their might be.
I'll post again when I have something in the way of analysis.
Addendum: I'm probably overreacting by claiming it gutted the Sony decision. My initial skim of the decision has only served to confuse me on what practical importance (if any) today's decision had. It definitely seems to make companies which promote copyright infringement to be dangerous to fund, but I'm not sure it goes beyond that, and it is far from clear that even a company like Grokster would qualify.
Addendum2: The best discussion I've found so far was here, on the SCOTUSblog.