You should double-check what kind of projects are being worked on before saying that it isn't being used for non-toy projects :) I can list at least two off the top of my head:

Q^3, which can render Quake 3 maps and will eventually be its own game: https://github.com/Jeaye/q3

Servo, an experimental web browser being written by Mozilla: https://github.com/mozilla/servo

For me, a non-toy project is a project that runs in production, where I can build my business on.

I love rust, but we have not yet finalized the syntax and the semantics yet, so it'd be risky to write mission critical things in it. Our plan is to hit 1.0 by the end of the year.

That said, rust has been written in rust, and every commit is tested against our test suite on Linux, OS X, BSD, and Windows. So while the language itself may be changing, any code you write in it at a given point in time should work. It'll just take some (small) effort to keep that code in sync with the compiler.

So if you are able to handle that risk, we'd love to have you try it out. It'd really help us find the warts in the language/stdlib before we lock in 1.0.

Rust isn't there yet in my opinion. The syntax and semantics are still undergoing development, and the standard library is still in the process of definition.

If you want to rewrite your codebase on a quarterly to cope with the changes, that's up to you, but I wouldn't.

I'm waiting for 1.0 to really start writing code in it.

There is also a Famicom/NES emulator written in rust: https://github.com/pcwalton/sprocketnes