Dennis Crouch at Patently-O published an internal January 7 memo from John Love (Deputy Commissioner of Patent Examination Policy) explaining the examination of process claims in view of In re Bilski. The memo is directed to the TC directors of patent examination.
In short, Love explained that the PTO is "presently studying the full ramifications of the court's clarification and other recent developments in the law." The PTO is in the process of redrafting the guidelines, and has recommended to the examining corps that the follow the current guidelines set forth in MPEP 2106, with the following modification.
As explained in a memorandum dated May 15, 2008, entitled "Clarification of 'Processes' under 35 USC § 101", a method claim must meet a specialized, limited meaning to qualify as a patent-eligible process claim. As clarified in Bilski, the test for a method claim is whether the claimed method is (1) tied to a particular machine or apparatus, or (2) transforms a particular article to a different state or thing. This is called the "machine-or-transformation test". It should be noted that the machine-or-transformation test from Bilski is slightly different from the test explained in the May 15 Clarification memo, which was based on the Office's interpretation of the law prior to Bilski.
There are two corollaries to the machine-or-transformation test. First, a mere field-of-use limitation is generally insufficient to render an otherwise ineligible method claim patent- eligible. This means the machine or transformation must impose meaningful limits on the method claim's scope to pass the test. Second, insignificant extra-solution activity will not transform an unpatentable principle into a patentable process. This means reciting a specific machine or a particular transformation of a specific article in an insignificant step, such a data gathering or outputting, is not sufficient to pass the test.
Read the letter in its entirety here (link)