Rust is a horrible choice now, because it hasn't stabilized. When it has stabilized, it may be a suitable choice (at one point, it looked like it would be too large of a language to a be a great intro language, but since then its been getting smaller, so I'm less convinced that it will remain unsuitable for that role.)

Python's a pretty good intro language; as is Scheme, and Haskell might be, though I haven't seen any good intro-to-programming material built around it, and while I think a good intro should prefer a largely-functional style (as the best Python and Scheme-based courses I've seen have), I'm not convinced that a pure FP language is ideal for an intro to the field (though it certainly a good thing to learn in the course of an education in the field.)