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.
Not to mention the approach to OOP is rather different in F#. It's syntactically and culturally different. Most OCaml programmers I know avoid OOP for the most part, whereas it's embraced to some extent in F#. Seems like a sort of "functional first, but feel free to use objects as you see fit" philosophy in F# versus a "functional always, objects are a failed experiment" philosophy in OCaml.
I don't mean to imply any judgment here, I'm just noting another difference between F# and OCaml.