Laurent Le Brun has updated the F# mode for Emacs. Enjoy!
If you haven't tried it yet, here are the main features:
It is important you use a recent version of Emacs, as it fixes a few problems. I recommend you to look at the README file for a complete description of key shortcuts. For instance, you'll learn that Alt + Enter automatically adds the ";;" before sending the expression, in the interactive buffer. Now, get fsharp-mode 0.3!