Can a U.S. Supreme Court decision be described as a watershed event only a few days after it is issued? Patent lawyers are debating that proposition in the case of KSR Int’l Co. v. Teleflex Inc., No. 04-1350, 2007 WL 1237837 ( U.S. April 30, 2007). KSR reshaped a complex set of rules developed over decades by the U.S. Court of Appeals for the Federal Circuit to determine when a patent that combines two or more previously known features — as many, if not most, patents do — is invalid as “obvious.” By refocusing the obviousness inquiry, and directing summary judgment invalidating the patent before it, this unanimous decision effectively calls on district courts to become more actively involved in striking down weak combination patents that are the result of nothing more than what the court called “ordinary innovation.”

KSR is one of three opinions this term reversing Federal Circuit decisions that had held in favor of patent owners — a trend that may indicate the court’s sympathy with those (including agencies such as the Federal Trade Commission) who contend that the patent system grants and then enforces too many questionable patents. After a long period when it seldom accepted a patent case, the court has now intervened decisively in the development of patent law, typically to limit the rights and procedural options of patentees.