That's assuming you care about concurrency in a low-level systems programming language. If my problem space requires concurrency I'd use clojure or erlang.
I guess if you're interested in one language for everything then maybe Go is better.
Go is not meant to be a low level systems language... it is meant to be a systems language useful for implementing services... something for which you better be caring about concurrency for.
Erlang really is the best language to point at and say "why do we need this new one", though doing that in the first place is stupid.
I guess if you're interested in one language for everything then maybe Go is better.