That's cool; but what is the point of haskell there? It sounds like you'd just as well could use, say, ruby; what does the specific feature set of haskell help here? (Apart from it being somewhat hard to actually write fortran code in haskell. :-)
Type safety would be the main plus point for me, even for tools and scripts.
Plus I guess some people just prefer functional programming when they can and Haskell offers that in abundance. I guess the downside is the less portable nature of the code (this is where Clojure et al. would probably win...although writing command line tools and scripts in a JVM language still has a long way to go IMO)
Actually, Haskell libraries were perhaps more important than any individual language feature. The language allows such good abstractions that libraries like Parsec or Haskell XML toolkit are very nice to use.