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.
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.