It would be cool to see a "layered" language. By this, I mean a language that has no typing at its lowest level, but you can add it as a library on top of the base level. Then you can add stuff like automatic resolution of calls, etc., as another abstraction level. Of course, you could also add other rules instead of typing. For example, you could pepper your programs with arbitrary proofs, etc., and this could be directed by yet another library on top of your program.

Perhaps I'm dreaming. But it sounds like useful to me, as there are so many languages that are almost similar, and yet are slightly different in the way they handle typing and things like polymorphism. It would seem to me that those languages could all share a common base.