The details are far from settled but in Alice v. CSL Bank, the US Supreme Court ruled 9-0 that a software patent is invalid.
From the opinion:
We hold that the claims at issue are drawn to the abstract idea of intermediated settlement, and that merely requiring generic computer implementation fails to transform that abstract idea into a patent-eligible invention.
If you want to buy a software portfolio, I would do it quickly, while patent holders are still in a panic. 😉