"A language that doesn't affect the way you think about programming, is not worth knowing" -- Alan Perlis
It's not solely just about if it is ready for commercial/real-world applications right now. The language itself is interesting and it definitely shapes a different mode of thinking.
Haskell is evolving rapidly and in interesting ways and those that are interesting in programming (as most of us here are), it's a good place to look and learn from.