@fwaris: We're working on switching over to the C# vNext [*] async pattern - we've been working on Orleans since long before it was available (even internally), so we had to implement our own version of promises. Once we switch, the F# async pattern will be very convenient, and F# would be a great programming language for writing grains. There's already another project in XCG that uses Orleans grains written in F#.

[*] edited: I earlier called this .NET 4.5, but realized it's been called a variety of names, so I'll stick with Anders' "C# vNext"