On June 1, 2009, the United States Supreme Court granted certiorari to hear the landmark Bilski v. Kappos case. Awaiting the Supreme Court’s decision, some district courts have exercised restraint by delaying their ruling on patent eligibility issues until the perceived uncertainty clears. For instance, one court has explained that “[a]fter the Supreme Court issues its Bilski opinion, this Court will likely have clear direction on the precise standard to be applied in evaluating the patentability of method claims. With that guidance, the Court will be able to efficiently consider and evaluate [the accused infringer’s] argument that the [patent-at-issue] is invalid.” Lincoln Nat’l Life Ins. Co. v. Transamerica Fin. Life Ins. Co., No. 1:08-CV-135-JVB-RBC, 2010 WL 567993, at *1 (N.D. Ind. Feb. 12, 2010) (citing Arrivalstar S.S. v. Canadian Nat’l Ry. Co., No. 08 C 1086, 20008 WL 2940807, at *2 (N.D. Ill. July 25, 2008)). This may be a prudent course, as the Federal Circuit Court of Appeals even “recognize[d] that the Supreme Court may ultimately decide to alter or perhaps even set aside [the Bilski machine-or-transformation] test to accommodate emerging technologies.” In re Bilski, 545 F.3d 943, 956 (Fed. Cir. 2008) (en banc)However, other courts have interpreted the Federal Circuit’s guidance in a manner that, if adopted by more courts, could cause material invalidity challenges to many patents. See, e.g., CyberSource Corp. v. Retail Decisions, Inc., No. C 04-03268, 2009 WL 815448 (N.D. Cal. May 26, 2009); Every Penny Counts, Inc. v. Bank of America Corp., No. 2:07-cv-042, slip op. (M.D. Fla. May 27, 2009); DealerTrack, Inc. v. Huber, 657 F. Supp. 2d 1152, 1153 (C.D. Cal. July 7, 2009); see also Assoc. for Molecular Pathology v. USPTO, No. 09 Civ. 4515, 2010 U.S. Dist. LEXIS 30629 (S.D.N.Y. March 29, 2010). This paper briefly reviews the Federal Circuit’s In re Bilski decision and details the Federal Circuit’s and district courts’ responses to it.