Don Syme has added some interesting features to F# like type providers, so I think it is OK to say that F# has transcended its OCaml roots to become an interesting language in its own right.
I don't mean to imply any judgment here, I'm just noting another difference between F# and OCaml.
Most people seem to think it's not syntactically very different: http://stackoverflow.com/questions/179492/f-changes-to-ocaml