F# ... Yes, Eugene, it's an Official .NET Language
Out in the field, some of my colleagues make fun of the fact that I still do my demos in VB. What can I say, having worked with VB since Day 1 and having programmed in Uni-BASIC, Applesoft BASIC, Commodore BASIC, GW-BASIC, QuickBASIC, and even VB for DOS, old habits die hard.
So when it mentioned from the Developer Solutions Specialist I work with that I should start doing my demos in F#, I thought he was pulling my leg. "F#...that's not a language." Well lo and behold, it's an official .NET language! Even though it was announced on the Microsoft Research blog, it's just as official as if it was announced on our main PressPass site.
I haven't tried it yet and I don't know when I'm going to start converting my demos over to F#, but as I start working more with Classic ASP and PHP into my demos, you can sure bet I'm going to start tinkering with F#.