F# will ship as part of Visual Studio 2010! Since the September 2008 CTP of F#, the F# team has been working hard on integrating F# into the main development branch of Visual Studio 2010, Don Syme. Essentially, F# is a programing language designed for the .NET Framework by Microsoft Research. However, despite the integration into Visual Studio 2010, it will not ship in the .NET Framework itself, and this also includes .NET Framework 4.0.

Source:→ Softpedia