I have the pleasure to announce restyle-0.1.0, a tool for the conversion of Haskell source between camelCase and separated_words style.
If you want to read your local haddockumentation in your favourite separated-words style, it can do that too, with a liberal choice of separation characters.
If you prefer to do your coding in separated_words, it may be as easy as one restyle to then deliver your cool library to the world in the prevalent camelCase (well, it'll probably take a few minor version bumps before that, but we can hope).
If you love underscores or hyphens, give it a try. If it sucks, at least it wasn't *your* wasted effort :)