Google's PageRank Patent in Jeopardy?

John Duffy has written an intriguing article over at PatentlyO about a set of recent cases/decisions putting all software patents running on general purpose computers in question; using Google's PageRank patent to demonstrate what's at stake. There's been a running debate in IP circles whether software patents would hold long-term, and as more online innovation focuses on just collecting and combining data in new ways, the attacks on software patents are getting more precise.

John shares some cases/quotes of note including:

In re Bilski: "[USPTO] takes the position that process inventions generally are unpatentable unless they 'result in a physical transformation of an article' or are 'tied to a particular machine'."

Ex parte Langemyr: “Any and all computing systems will suffice, indicating that the claim is not directed to the function of any particular machine. … Thus, the claimed method is not tied to ‘a particular machine,’ but rather is tied only to a general purpose computer.”

Ex parte Wasynczuk: “the sole structural limitation recited is the ‘computer-implemented system’ of the preamble” and that limitation “is not any particular apparatus” because the computer could be “essentially any conventional apparatus that performs the claimed functions.”

If you're in the software business, this is a topic worth watching...