[ufo]

The nice thing about Haskell is that the type system lets you work at a higher level of abstraction. One of the problems with dynamically typed languages is that even though they let you create abstractions they are bad at error detection. For example, if you have a function that expects non-null inputs and you pass null to it the error is only going to be caught when you try to call a method on the null. On the other hand, in a statically typed language you get an error message poining directly to the real source of the issue.

Another othing Haskell gets right is the support for parametric polymorphism (generics). You are forbidden from manipulating generic parameters other than passing them around so there is less room for error. This "theorems for free" is what makes things like monads "tick".

That said, one thing that is in vogue right now is adding optional type systems and runtime contracts to scripting languages. Its still a bit of a research area but I think it has a very promising future.