This is a reasonably substantial project involving a professional design agency and a review of the current content (and how it's arranged).
The aims of the work are described on the infrastructure mailing list  and any interim files, sketches etc will be made available via that list and the gihub wiki .
There is now a wireframe walkthrough of the site design at http://amirchaudhry.com/wireframe-demos-for-ocamlorg
Been a while since I updated this thread. There is a redesigned version of the site at http://ocaml-redesign.github.io and we will shortly be merging this design into a fork on the main repo.
Closing this as the redesign is well underway and close to being made live.