[saidajigumi]

As neovim matures I think the opportunities for rich extension and scripting are going to blow away anything vi/vim users have ever had. I think ex-mode could be reimplemented as you suggest, or we'll end up with other awesome approaches that were simply unthinkable in the old architecture and codebase.

[dllthomas]

It looks like tarruda explicitly says, "As for the ex command-line utility, that can easily be implemented as separate program that talks to nvim via msgpack-rpc".

This seems like a reasonable separation of concerns.