That sounds like it would definitely be a good benefit to the community and I'd be really happy to do it. I know that ppx is the successor to camlp4, and I have a mind to teach myself the sort of magic where I can annotate a type with some code generating function because I appreciate the power.
But right now, my extra curricular work is just ridiculously over loaded. In my free time I'm teaching myself Coq, compiler construction with llvm, taking a coursera course working on a shingled disassembler, working on an ocamljava backend for ctypes and a ocaml link to CZMQ. I love what I do - coding and learning all day long - but I have human limits, and I just don't think I would be able to pick it up for probably 6-8 months. Possibly something else will come along before then, whether that be even more compelling challenges or that ocamlviz is seconded by something better.
So, I really honestly would, but I don't think I can. :(