The goal is to add other features that are also useful for scripting. The big one I've worked on so far is syntax for the os/exec package: https://github.com/neugram/ng/blob/master/docs/shell.md#a-sh...
Another thing I'm interested in is operator overloading, for compact/pleasant matrix/table types.
It's a novel idea but I don't really see it taking off. Is there really that much benefit to having a shebang at the top of the file versus executing "go run" and is it really worth having a REPL for a fairly verbose language? I certainly don't see myself wishing for a Java REPL, and I don't particular see myself reaching for a Go REPL either.