The number one problem with commercial OCaml is the lack of comprehensive library support. Until that's addressed, it's not going to take off. Brilliant language, not very practical. F# is a step in the right direction here.
During the same time using GODI to install a xml processing library completely hosed my system after me foolishly granting it root rights, which killed my OCaml enthusiasm for good.
OCaml is in itself a really nice language (apart from some warts like lack of native multithreading support) but it's tooling, infrastructure and "first developer experience" and lack of progress in these areas in the last years is beyond atrocious (compared to F#, Scala, Clojure, Haskell, Ruby, Python, JavaScript).