This sounds like it could be useful for me. I've never so much as looked at Nix; if i go and read the standard documentation, will i learn how to do this? Or is it a creative application of the tools?

Does Nix make it easy, or even possible, to bring in dependencies from legacy sources on the network? For example, my company has an FTP server full of carefully-packaged, versioned libraries in tarballs, and it would be great to be able to use those, rather than having to repackage everything.