[Haskell-beginners] Haskell and Niches

The recent mailings about using Haskell for an accounting system got me thinking, since people have pointed out the things that would make the language suited for the task. Does this means there are some programming tasks that Haskell is great for, and others that you would pick a different language for? I was under the impression that it was more a "general purpose" language than a "niche" language--I'm using it for programming a decently ambitious (though small) game now, and it's bending my brain but I suspect it is fully possible even though games are traditionally imperatively programmed. Do you try to use Haskell for every project? Is there some sort of "right tool for the right job" adage you follow?