You practically need a Venn Diagram to understand who said what on what is, on its face, a 9-0 decision!
* Opinion: Roberts, Thomas, Alito
* Opinion minus two sections: Kennedy, Scalia
* Concurring opinion 1: Stevens, Ginsburg, Breyer, Sotomayor
* Concurring opinion 2: Breyer
* Concurring opinion 2, Part II only: Scalia
Wendy Seltzer suggests in "Bilski and the Value of Experimentation" that the confusion arises because patent law is unique--- all appeals are funneled through a single court, the US Court of Appeal for the Federal Circuit. This short-circuits the normal process by which multiple circuit courts may look at the same issue, and arrive at either a consensus view or a clearly defined split. The Supreme Court can take advantage of these multiple viewpoints in crafting a test or clarifying the law. As Seltzer writes:
Circuit splits are good for judicial decisionmaking. They permit experimentation and dialogue around difficult points of law. (The Supreme Court hears fewer than 5% of the cases appealed to it, but is twice as likely to take cases presenting inter-circuit splits.) Like the states in the federal system, multiple circuits provide a “laboratory [to] try novel social and economic experiments.” Diverse judges examining the same law, as presented in differing circumstances, can analyze it from different angles (and differing policy perspectives). The Supreme Court considering an issue ripened by the analysis of several courts is more likely to find a test it can support, less likely to have to craft one from scratch or abjure the task. At the cost of temporary non-uniformity, we may get empirical evidence toward better interpretation.