In addition, we've only had a stable Rust for six weeks: there just hasn't been enough time to write more advanced things. Nobody wants to invest in stuff while things are still changing. As an example of this, I know there's an O'Reilly book coming out in the fall which covers advanced topics exclusively.
A basic task pool isn't too many lines of code: https://github.com/rust-lang/threadpool/blob/master/src/lib.... Hopefully that can help for that case, though obviously, this isn't just a comment about threadpools :)