If you or your organization have been using F#, you can also submit your own testimonials using these simple instructions. They can be your personal views, and you can anonymize as necessary.
p.s. For those who haven't heard, the F# Software Foundation (a.k.a "fsharp.org") is a community-led group. You can read its mission statement on the site. I think it is a great initiative that acts as a wonderful complement to the investments both Microsoft and other groups are making in the language. If you're into F#, I'd encourage you to become a member (just email email@example.com) and to contribute.