Is it worth trying to learn Haskell Yesod vs. say, becoming advanced with python & django?
Python has a less steep learning curve and has a more vibrant ecosystem.
Haskell has the potential to change the way you think about programming, and its ecosystem is maturing quickly.
I used Haskell for my university honours thesis. Spent a whole year on it but still haven't had the chance to fully grasp the concept of monads yet, but I'm not sure its because they're complicated or because I didn't need them.
I use python + django at my day job.
I suspect Haskell will become a lot more popular in the long run though. (Maybe in 5 years time).
So go python. :)