I'm not too clear on the details since I don't know the language, but I think that Rust's (http://www.rust-lang.org/) concept of "ownership" does something very similar to what you're suggesting.

Go allows pointers to be sent over channels, so it's up to you to make sure you send copies of data to prevent problems. So no, I'd say Go isn't doing that; or rather, it does require message passing but there's a huge loophole which means you basically can share mutable state unsafely.

Rust, on the other hand, is much closer to what you're describing.

in clojure there's something similar called transients http://clojure.org/transients