I work with .NET by day and after spending quite a bit of time learning Lisp, I can tell you that even with a killer feature like that, it's not even close.
F# might not be as conceptually cool as lisp (I don't know enough of either to comment yet), but I would bet that enterprise users, especially those who already have a .net codebase, would rather switch to F# than lisp. Not to mention that in the case of the former, it wouldn't have to be a switch; F# is meant to be used alongside C# instead of replacing it.
You're right about the probability of .net coders using F# over lisp. That said, F# is still a very big conceptual leap even if it does compile down to IL and run alongside all the other CLR compliant languages. The leap is having to shift your thinking from object-oriented programming to value-oriented programming.
The number of language users is not a function of how good that language is (ask PG or any lisp advocate!).
I will almost certainly learn F#, for some of the reasons above, but I don't think it'll ever match the elegance and succinctness you get with Lisp.
I agree that the number of users is not a function of how good the language is. And you are right about the conceptual difference between C# and F#. OCaml from the beginning prioritized practicality instead of elegance, so you are surely right that F# will never match the elegance of lisp. That isn't the goal though.
