I imagine everything said in the article also applies to the Nix package manager[0]. One of its nice features is the Nix expression language (aka Nix) [1]. It has an elegant mixture of purity and pragmatism. I imagine guile scheme would have a lot more integration opportunities outside of just system/build/configuration management. It'd be interesting to see Guix expressions that actually mix other scheme libraries or concepts, rather than just taking Nix expressions and removing the syntax.
[0]: http://nixos.org/nix/ [1]: http://nixos.org/nix/manual/#chap-writing-nix-expressions