Supreme Court Line-Up
Majority (opt-in): Roberts, Scalia, Kennedy, Alito, Thomas (although he didn't speak)
Minority (opt-out): Breyer
On the Fence: Stevens, Souter Ginsberg
Altogether, this is at minimum a 5-4 decision in favor of opt-in, with the potential for an 8-1 or even unanimous decision if Justice Breyer (a reasonable man by all accounts) can be persuaded.
Stay tuned for commentary on the decision as it emerges.