There exists at least one UK university which uses Haskell as a teaching language in its CS department. Not quite 7 year olds, but certainly a good percentage of fresh programmers.
Does it result in better programmers? Perhaps. It certainly forces you to understand recursion.
My university used Haskell as the intro language for the math department. People who where already good at programming and people who had never programmed before picked it up quite quickly, but people in the middle who knew a bit of programming coming in had a terrible time with it.
However people who'd never programmed before the Haskell course had a very hard time transitioning that knowledge to Java and similar languages, which was used in some other courses.
I remember learning Haskell at Imperial College London - a very nice language. I had never tried a functional language before and just loved how "natural" if felt after getting familiar with it.
I would love to re-learn it but I am thinking that from a career point of view I am better off learning Scala/Clojure than Haskell.
Does it result in better programmers? Perhaps. It certainly forces you to understand recursion.