Would you have played if you could choose Python or CoffeeScript, or would we have to be epic and write a Haskell -> JavaScript transpiler to pass go?
If you can integrate haste or fay and let people play in Haskell that would be indeed be epic, and I would definitely use it (as haskell is my learning project at the moment)
I don't know Haskell, but I would have considered learning it if it was offered. ;)
There are at least three of them already - UHC's JS backend, Haste and Fay.
Could be fun.