You should check out Neovim. The native scripting language is Lua, and it's a fork of the vim codebase so still fast and commands all work identically. It's still early, but I am monitoring (and supporting) the project closely.

Also, one of Neovim's banner features is asynchronous job control, which greyrest complained about.

I can't wait until we don't have to run it in a terminal though.