[johncolanduoni]

Well both of those things basically already exist; you can do conditional compilation based on architecture, etc. and macros can do some of the less hacky things a preprocesser can (as well as many things it can't).

The biggest Rust project (which already has many of the core contributors working on it) is Servo, and it's probably about as ambitious as you can get while still having a nonzero chance at completion. I don't think there's much additional value in taking on a completely unfinishable project to shape the Rust language so it's good for a kind of programming (i.e. Kernel programming) that is far removed from what 99% of potential users will use it for.