[mikepurvis]

I might just lack imagination, but I think the wheels are already well in motion for at least one significant piece, which is many more upstream maintainers having some awareness of Nix and Guix (and now Tea too, I guess) and understanding the value of things like reproducibility, relocateability, not accessing the network during build, not making assumptions about where stuff will be located or that the different build outputs (lib/bin, dev, doc, whatever) may end up in fully separate trees. This goes doubly so for tools maintainers like the people at Kitware, who wield an enormous amount of power in steering devs toward patterns that allow software to be packaged for Nix with minimal patching.

All this lowers the fragility of the package definition and I think helps increase the likelihood of that software being forward- and backward-compatible with different versions of its underlying dependency pool.