As a current python & rust user, I can say that I picked up rust because I liked the idea of a systems language that could give me c-like performance, without having to use C. Rust seems, to me, like a combination of the best parts of python (traits as pseudo-duck-typing), haskell (type inference, functional concepts), and C(++) (speed, no GC).
As @mitsuhiko says in the article, it is very easy to export symbols from a Rust library so that they can be used via CFFI, so the possibility of "dropping down to Rust" instead of "dropping down to C" is very attractive to me.