My personal history goes something like QBasic -> Visual Basic -> PHP -> Java -> C# -> Haskell.
Since Haskell is a purely functional language there's no cheating like you could in, say, OCaml. This forces you to learn how to work with immutability, which I have become a big fan of. When working with C# I try to avoid mutability as much as possible (naturally this is quite a bit uglier than in Haskell, but it does avoid some problems). Most of my C# projects now acquire a Haskell.cs file fairly quickly, containing things like a Tuple class, zip, >>=, etc.
In the time I've spent learning it, Haskell has quickly become my favourite language. It's not perfect (my current main wishes are existential types and an extensible record system), but it is considerably less painful than the other languages I know.
As for speeding up the transition, I can't offer anything other than just diving in. At some point it will just click and you will wonder what all the commotion is about (another monad tutorial? why?). Granted, I still don't have the slightest idea about why I would want to use a hylomorphism or what to do with a comonad, but perhaps I will some day. Fortunately you don't need them in everyday Haskell programming :)