I'm not a big OCaml user, have used it on occasion for a few small projects and I liked it, but from what I remember, I think a few things are missing from this list if OCaml wants to obtain widespread adoption.

1. Really good unicode support

2. A dead simple high quality package manager i.e. bundler, mix, cargo.

I'd also add built-in concurrency primitives i.e. (Channels in Go, Processes in Erlang), though this probably isn't a must have currently, but will surely only become more important as time progresses into the multicore future.