Haskell isn't as hard as people like to make out to learn. Haskell opens up a new world that you never knew existed for you. It's as valuable to learn as any other language. You might not find a job requiring you to do Haskell programming, but does that really mean a language isn't valuable?
Haskell will teach you a lot of new stuff, and it will show you how to program even better in the languages you /do/ work with. You can do your own personal projects in your spare time with it.
Haskell isn't really used much in the "real world" if you define "real world" as "cash generator". So if that is your objective, then you might have to rethink objectives :p
Also, I don't really like that part of chosen "how to learn haskell" answer. It takes months to years to master any language, not just Haskell. Depending on how you define "master". I can use Haskell to a pretty good degree of efficiency and I've only been learning it for a month, and I've been taking it slow even.
