The very interesting session from PDC10 related to the future of F# - Microsoft functional-object-imperative variance of OCAML.
They are extending application with "type providers", which allow to extend static type system of F# with dynamically generated types withoun explicit code generation - by implementation of a very simple interface.
I think it can be useful techique to implement business platforms such as LightSwitch (when it come to C#) - LightSwitch authors can just implement type provider for entities and do not generate very much intermediate code.
PS. I think there is aplso enteresting how easy Don manipulates various data in F# interactive