I don't think this article quite hits the nail. Specifically, its interpretation of the ruling is wrong (though IANAL). Having said that, this is certainly a positive ruling (if you are, like me, opposed to software patents), and in general my impression is that the trend is clearly against software patents. I'm not sure if there is any software patent the court would eventually uphold, but it generally prefers to avoid such sweeping rulings on matters that are not immediately before it. That is, the court is not entirely sure that no software patent can pass the muster, so it prefers to wait until it sees more credible software patents (like compression algorithms, apparently) to rule on those.
The article claims the Supreme Court ruled that the "invention" is not patent-eligible because "each step does no more than require a generic computer to perform generic computer functions". However, this is not the whole analysis and is akin to saying that no electrical circuit can get patent protection if it can be divided into basic components.
Let me quote the relevant parts from the ruling.
In Mayo, we set forth a framework for distinguishing patents that claim laws of nature, natural phenomena, and abstract ideas from those that claim patent-eligible applications of those concepts. First, we determine whether the claims at issue are directed to one of those patent-ineligible concepts. If so, we then ask, "[w]hat else is there in the claims before us?" To answer that question, ***we consider the elements of each claim both individually and "as an ordered combination"*** to determine whether the additional elements "transform the nature of the claim" into a patent-eligible application. We have described step two of this analysis as a search for an "'inventive concept'"--i.e., an element ***or combination of elements*** that is "sufficient to ensure that the patent in practice amounts to significantly more than a patent upon the [ineligible concept] itself."
(page 7, emphasis added, internal quotations removed)
That is, the "elements", or the steps the algorithm in question performs, are to be considered both individually and as an ordered combination. The article somehow reads the second prong of this analysis entirely out, but such a reading is not faithful to the decision. Similarly to how an electrical circuit that consists of basic components can still merit patent protection, the court leaves open the possibility that an algorithm composed of "ordinary" steps might be eligible if the steps "as an ordered combination" contains an "inventive concept" that is "sufficient to ensure that the patent in practice amounts to significantly more than a patent upon [an abstract idea] itself".
The text that the article quotes is from page 15 of the ruling:
***Taking the claim elements separately***, the function performed by the computer at each step of the process is "[p]urely conventional.". Using a computer to create and maintain "shadow" accounts amounts to electronic recordkeeping--one of the most basic functions of a computer. The same is true with respect to the use of a computer to obtain data, adjust account balances, and issue automated instructions; all of these computer functions are "well-understood, routine, conventional activit[ies]" previously known to the industry. In short, each step does no more than require a generic computer to perform generic computer functions.
But this is only the paragraph that analyzes the claim elements separately. What the article does not recognize is the paragraph that immediately follows:
***Considered "as an ordered combination,"*** the computer components of petitioner's method "ad[d] nothing . . . that is not already present when the steps are considered separately." ***Viewed as a whole***, petitioner's method claims simply recite the concept of intermediated settlement as performed by a generic computer. See 717 F. 3d, at 1286 (Lourie, J., concurring) (noting that the representative method claim "lacks any express language to define the computer's participation"). The method claims do not, for example, purport to improve the functioning of the computer itself. See ibid. ("There is no specific or limiting recitation of . . . improved computer technology . . . "). Nor do they effect an improvement in any other technology or technical field. Instead, the claims at issue amount to "nothing significantly more" than an instruction to apply the abstract idea of intermediated settlement using some unspecified, generic computer.
So, the fact that an algorithm only performs "purely conventional" steps is not the end of the inquiry; it just may be sufficient that such an algorithm when viewed as a whole ("ordered combination") may warrant protection.