We'll see. For inline assembly, sure, it doesn't, but you can do some pretty intense stuff with Rust's type system to guarantee certain static properties. For example, earlier today this comment appeared on Reddit, talking about how to use the type system to guarantee that you're not doing out-of-bound array accesses: http://www.reddit.com/r/rust/comments/3aahl1/outside_of_clos...

It is true that the lower you go, the less we currently offer, but over time I expect library authors will use this and other future features to check even more properties without runtime overhead.