From what I've seen of the overall software ecosystem so far, I very much like this answer. Rust was designed to be more of a general programming language, replacing a lot of the things you'd typically use Python or C++ for, instead of being driven by a particular GUI (Swift) or web (Ruby) framework .
Rust is already being used for web servers, so it is quite feasible that you can use a web UI instead of a traditional desktop app. This also benefits from cross-platform out of the box, thousands of existing JS and CSS frameworks for the front end, and loads of information on the internet for making a web UI backed by a server.
I reckon something like Rocket + React would work quite well, plus it gives you a nice separation of concerns that GUI programs tend to lack. I've seen my fair share of GUI programs where the front-end logic and application logic is one tightly coupled ball of spaghetti. Web apps with a server-client model tend to not have that problem.
I'm not sure to be honest, Rust can easily interoperate with C so creating a pure-Rust toolkit which binds to the Windows windowing API is technically feasible. Likewise, there are already crates which can communicate with Wayland or X on Linux. There are also some nice solutions like Conrod built entirely Rust in Rust, plus libraries like Relm fit Rust's feel a lot more idiomatic than all the other GUI toolkit bindings I've tried so far.
Whether any of these really take off though, that's an entirely different question.