Haskell seems extremely neat, and I do like the ML family for compiler development, but Haskell just seems like such a steep learning curve. The amount of operators I've seen boggles my mind, are they user defined? Is there a good way to learn Haskell that preferably skips over some common functional concepts?
I'll put the learning curve around the same level as C++, with the qualifier that most of what you learn aren't parts of the language, but patterns and formalisms you can use in any language.