We have pattern matching, traits, generics, etc. in Scala (and OCaml?) already. The syntax isn't the same, but draws from the same lineage. If you took away the memory management, I think Rust would be just another ML descendent and I don't know what the motivating feature for the language would be.

I could be off base. I haven't programmed in Rust. I've just skimmed through the documentation and little code projects written in it every once and a while.