I read Somasegar's post on "productizing" F# (man, that sounds ugly!). In general terms, I think this is a great idea; there are many concepts in F# that would be very welcome in a mainstream, supported tool, and I can see a lot of potential for, say, mixing C# and F# solutions together, as each one has its strengths (and add to that a bit of IronRuby to top it off).
Multi-language solutions do become a more interesting proposition when there are clear relative strengths and clear differentiation between languages, such as functional vs. imperative, dynamic vs. static; so it is a completely different proposition than, say, the old argument about mixing VB.NET and C# (which made little sense for most purposes).
On the other hand, am I the only one that had to read three or four times Somasegar's post to see what the deal was? Heck, in fact, I'm still hazy on what exactly "integrate the F# language into Visual Studio and continue innovating and evolving F#" will really mean.