Steven's concurrence is actually a dissent in part. He goes on for 40+ pages about why business methods should not be patentable under 101, and three other justices joined Stevens. Regardless of whether he label his writing a concurrence or dissent, the opinion is split. There is a 5-4 majority opinion in favor of business method patents.

Practically speaking, this means that the Court is one vote away from making business methods non-patentable.

Software patents are still good. The court seems to unanimously agree to maintain the status quo that software methods are patentable subject matter.

Business method patents are still good, but just barely. The opinion is split 5-4 in favor of business method patents, but puts some rather vague restrictions on them (e.g., must not be abstract ideas).

My read is that the justices seem to be ok with software patents in principle but are leery of business method patents that are not tied to a device or that do not incorporate some form of technology.

They seemed to struggle with how much of a "machine" needs to be added to an abstract business method before it becomes patentable subject matter.

In other news, Roberts appears to be confused about the difference between patentable subject matter and obviousness.